Holistic Review: A sublime evocation of a 1990s television adaptation of an Agatha Christie novel, and the writing is whip-smart.

I know I wasn't terribly keen on the idea of "the Orient Express in space", but I must give credit to writer Jamie Mathieson for making it work so well. My knee-jerk reaction last week was to remember my disappointment with the similarly-anachronistic Voyage of the Damned, but Mummy on the Orient Express is more successful in this respect because it sustains an authentic 1920s atmosphere, whereas the space-Titanic was full of aliens and robots that immediately shattered the fantasy. Here, even though the only thing outside is the vacuum of space, inside the train it feels convincingly like the 1920s. (It also helps that Mathieson lightly pokes fun at the time-period mash-up idea, just once, as the Doctor declares that the Orient Express is dedicated to "painstaking attention to detail" just before a man wearing a steampunk monocle brushes past.) Although the story could have been set in the 1920s without requiring any drastic changes, I didn't feel that the futuristic setting detracted. If for no other reason, it provides an unproblematic justification for the monster. As Professor Moorhouse points out (and as last week's episode ably demonstrated), while we might baulk at the idea that an ancient Earth mummy was being kept alive with alien tech, we have no such reservations about a legendary space mummy, because anything is possible in space.

After last week's scripting débacle, Mathieson's dialogue is a soothing balm. Appropriately for an homage to Agatha Christie, every line contributes to the plot, and aside from a handful of possible plot holes that I'll discuss below, the story's internal logic holds together. Cleverly, the Doctor's examination of Mrs Pitt's Life Extender turns out to be a great big obvious hint, because the Foretold is likewise powered by "tech that keeps it alive!" Mathieson is even able to write a convincing exposition scene, using a setup in which the Doctor tries to prompt Professor Moorhouse to realize just what's so odd about the Foretold appearing on this particular train. As Mathieson previously wrote for Being Human, I'm not surprised that I found his script to be so engaging, but then, prior successful credentials aren't necessarily a predictor of how well a writer will handle Doctor Who. Based on the evidence from this episode, I'm eager to see him return to the fold, and since he also wrote next week's episode, I won't have long to wait before we find out if Mathieson is a major name to watch.

The Foretold turns out to be quite the creepy monster. I don't know if I'd go so far as "scary", maybe because it's only scary if it's coming for you, but its method of only being visible to its victims, who have a clearly delineated remaining lifespan, and the fact that it's inescapable once it has you in its sights, reminds me of the very frightening Ringu. The monster's decrepit design is certainly fantastic. With its rotted leathery skin, exposed bones, decaying teeth and dusty bandages, it looks every inch the classic film mummy, which makes it an interesting contrast to the hulking, imposing, pristinely-bandaged mummies from Pyramids of Mars. Also in contrast to the stiff, lumbering gait that the Pyramids mummies have in common with many mummies from the silver screen, actor Jamie Hill adopts a shuffling zombie-like movement, with the Foretold's feet dragging almost uselessly along the floor as it walks, although he's preserved the spine-tingling idea of the mummy reaching out for its chosen victim. The Foretold's inner tech is also creepy, attached as it is to something organic and seaweedy, which gave me the impression of dusty, mummified, yet unnaturally supple blood vessels.

The Foretold's backstory is left tantalizingly unexplained, but extrapolatable. It's not difficult to imagine that a scientifically-advanced race, mired in a devastating war, might make the ethically-bereft decision to create a device that would keep their soldiers alive after death. Professor Moorhouse observes that the Foretold appears to have been "peat bog preserved", which suggests that the mummy was reanimated and forced into soldiering some considerable time after its death; perhaps the war in question was so long and bloody that the government ran out of eligible living soldiers, and were forced to resort to reanimating the long-dead? Given that the Foretold is apparently unique, perhaps it was a test subject, and no other mummy-soldiers were created because one Mummy of Death turned out to be more than sufficient, or perhaps its creators had an attack of conscience. Either way, the mummy is a perfect soldier: not only is it unkillable, it needs no weapons because it is the weapon, able to strike fear into the hearts of the enemy and murder them with a touch, until it finally forces a surrender. One can only surmise that its original enemy never did surrender — perhaps they actually won the war, and vanquished the mummy's creators, leaving no-one with the knowledge to deactivate it while the mummy continued its murderous rampage through the centuries. Once we learn the Foretold's backstory, it becomes an almost tragic figure, forced against its will to continue fighting a war that ended long ago.

Once a character sees the Foretold, an onscreen clock shows their remaining 66 seconds of life ticking away. At first, I felt the clock was a redundant, overwrought gimmick, but by the second or third death I had grown to really appreciate it, because each death is unambiguously timed to precisely 66 seconds. With the clock onscreen at all times, for once I don't have to independently verify the accuracy of the countdown (which never turn out to be correct anyway). So this is a breath of fresh air, and makes me very happy. Stories featuring bombs with countdown timers could learn a thing or two from this episode. The countdown clock also enhances the misdirection when the sarcophagus opens, as we expect the Foretold to emerge and attack Clara or Maisie.

Despite its strong Christie influences, Mummy on the Orient Express isn't your typical whodunit. Before the teaser even ends, we know perfectly well whatdunit. Much like in The Robots of Death, what we don't know is who organized this trap. Who selected this complement of passengers, and who arranged for the Foretold to stalk the train? We find out the answer about halfway through: the mysterious Gus, chummy voice of the train's computer and mysterious agent pulling the strings from off-screen. His role, as the unseen sociopathic observer whose whims control the lives of everyone he has trapped on the train, is creepily reminiscent of films like The Most Dangerous Game or House on Haunted Hill or even Saw. For now, Gus' true identity remains a mystery. The obvious candidate is Missy, but this doesn't seem to fit her style at all. Not that we really know yet what her style is, but as far as we can tell, she seems to prefer letting the dead come to her, rather than going out and killing people herself, and it's not clear why she would want to reverse-engineer the Foretold's ability. But Clara's right that if Gus wants to stop them from using the TARDIS, he almost certainly knows who the Doctor is, so chances are good that he's a returning enemy. All we really know about him (assuming "male" is accurate; after all, we've already seen the Doctor utilizing voice-altering technology this season) is that he values scientific research, and he's interested in developing technology that can drain cellular energy, but this doesn't really narrow it down. It could be anyone from the Rani to Magnus Greel to the Sontarans, depending on the purpose to which he plans to put the technology. And it occurs to me now that, since the Zygons, we haven't yet had any "new" returning monsters this season, so I hope my general theory is correct. At any rate, it seems unlikely that we've heard the last of him, so presumably the mystery will be cleared up sooner rather than later. (Unless Gus is this season's "woman in the shop", in which case we might have to wait a while.)

I hadn't even realized, until I was looking over the episode's Wikipedia entry, that the Doctor's mention of Gus having "phoned the TARDIS once" is a reference back to The Big Bang, in which the eleventh Doctor answered the TARDIS phone and said "An Egyptian goddess loose on the Orient Express, in space?" Unless the Egyptian goddess was all a ruse, that line implies three things: (1) to our knowledge, Gus' experiments have thus far been limited to interplanetary trains; (2) Gus has not, however, been limited to studying the Foretold; which further implies that (3) Gus is keenly interested in studying the Doctor, in particular. This all suggests that he has some ulterior motives beyond simply learning how to drain cellular energies.

The Doctor and Clara are rapidly developing the most interesting, complicated Doctor/companion relationship that we've had in the new series. On first viewing, I was surprised that Clara suddenly decides to keep travelling with the Doctor, but actually the seeds are planted and reinforced throughout the episode. For that matter, some are planted before the episode even starts. I was perhaps even more surprised, and more than a little thrown, when Clara followed the Doctor out of the TARDIS — why was she there, willingly, and apparently having fun? I was all set to chide Mathieson for a continuity error even worse than Rose and Mickey's suddenly-not-at-all-tense relationship in The Girl in the Fireplace, until the Doctor chides Clara for putting on a happy face, and her joyful expression evaporates. Maisie explains this really well later, when she points out that Clara could very well have given up the Doctor cold-turkey, but for some reason, she didn't. That reason gradually becomes clear over the course of the story, as we realize just how invested Clara is in the Doctor's lifestyle. Her resolve has already begun to weaken by the time we join them; while Clara still feels that she can't continue living the Doctor's lifestyle, she's moved on from having hated him for weeks. But it's clear that she still finds it thrilling, especially when the Doctor points out that she seems to want there to be a monster on the train for them to defeat. When Danny mentions that their current trip isn't "dangerous", Clara tellingly responds "Yeah, it's pretty boring, really." So, when the Doctor tries to keep her out of the action (and any danger that comes with it), it's no huge surprise that Clara gets stroppy, because despite what she told the Doctor, she does want to be involved. She couldn't give it up even if she wanted to. And I get it, because the Doctor would be almost impossible to give up, wouldn't he? What's worrying is that Clara is now lying to both the Doctor and Danny about her change of heart, which is bound to come back to haunt her later.

It's a shame that Clara winds up stuck in the baggage compartment for the lion's share of the episode, unable to contribute to the plot in any meaningful way. It's certainly not a bad story for her, given the amount of airtime that's dedicated to her gradual change of heart, but her best moment is when she suddenly finds herself a willing party to the Doctor's deception, lying to Maisie in order to lure her to the research laboratory. I was pleading with Clara not to lie to her, and shocked when she did. Along with her infuriated delivery of "Okay, this! You see, this! This is why I'm leaving you, this, because you lied. You lied to me again, and now you've made me lie. You've made me your accomplice!", Coleman gives a great performance as Clara attempts to interrupt the Doctor to let him know that "I'm trapped!" as well as the line "Yeah, they happen." I really love Clara's glittery black-and-gold 1920s dress and her very flattering bob haircut. If not for Robot of Sherwood, this would be my top look for her character. There's a great moment, when she runs after Maisie into the locked baggage compartment and glances over her shoulder, when she looks every inch the flapper, right down to the body language.

I know it's nothing new, but I just have to say again that I love that the show is taking such risks with the Doctor. While I'm glad he's stopped pretending to abandon Clara to the monsters, his tendency to manipulate people and his refusal to coddle anyone gives his character a refreshing ambiguity and unpredictability. In the line below, I actually had a moment of uncertainty as I tried to decide whether the Doctor really was kidding:

Clara: "So you saved everyone."
Doctor: "No, I just saved you, and I let everyone else suffocate. Ha ha ha."

Surely this is the only Doctor we wouldn't automatically trust when he says he rescued everyone. By this point, we know full well that he'll lie to people if it'll get him what he needs, although interestingly the concept of a white lie seems to be foreign to him. I mean, just look at how he tries to persuade the doomed Professor Moorhouse to help: "Even the smallest detail might help us save the next one!" Predictably, this suggestion backfires. His line "Well, of course not for you, because you're going to die, but I mean, for us, from a research point of view..." is so callous that it's almost reminiscent of the Rani's viewpoint. The twelfth Doctor's lack of sentimentality has become a defining character feature, to the point that he's even more prickly than either the first or sixth Doctor, which is really saying something. Yet it's clear, particularly in this exchange, that although the twelfth Doctor is insensitive, and bluntly realistic about being unable to save people from certain-death situations, he's not deliberately cruel:

Clara: "So when you lied to Maisie, when you made me lie to Maisie, you —"
Doctor: "I couldn't risk Gus finding out my plan and stopping me."
Clara: "So you were pretending to be heartless."
Doctor: "Would you like to think that about me? Would that make it easier? ...I didn't know if I could save her. I couldn't save Quell, I couldn't save Moorhouse. There was a good chance that she'd die too. At which point, I would've just moved on to the next, and the next, until I beat it. Sometimes the only choices you have are bad ones, but you still have to choose."

And even in the heat of the moment, he does at least attempt to rationalize his heartless-seeming behavior: "People with guns to their head, they cannot mourn. We do not have time to mourn." Outside of these dire situations, for the most part the Doctor channels his ferocity into defeating the bad guys, or wielding his righteous indignation like a weapon. His entire confrontation with Quell shows off the best side of his character. He has no patience with Quell's indifferent authority, dressing him down with the excellent line "Yes, let's just sit around and wait for the evidence while the bodies pile up. Or here's a crazy thought: we could do something to stop it." In that sense, especially, this is a really good story for the Doctor: he takes utter control of the situation, and he and Perkins are the only ones who seem to be thinking through the situation logically. He may demonstrate an ego on par with the sixth Doctor when he declares, "One minute with me, and this thing, it would be over!" but the thing is, we believe him. Indeed, when the Doctor does finally confront the Foretold, this turns out not to be idle bluster. As promised, he has it crumbling to dust within 66 seconds of brilliant deductions, even allowing for several off-topic asides. Along with the aforementioned lines, Capaldi gives a great delivery of: "All gone now.", his body language as he tries to decide whether to wake Clara (before thinking better of it), the way he motions for Moorhouse to shake his hand, his resigned expression as he motions Perkins to follow him, "I didn't know! I certainly hoped...", and "You can't hurt me until my time is up. I think."

I'm generally happy if a Doctor Who guest character is given a convincing personality sketch in one line. Sometimes this works really well, like Saibra in Time Heist, and other times not, like Lundvik in Kill the Moon. Mathieson not only succeeds at this, he follows in the Robert Holmes tradition of suggesting realistic backstories through a few well-chosen words. Captain Quell (David Bamber) is an excellent example: on the surface, he's just your average rule-enforcing train captain, who arrests the Doctor as a possible stowaway. But we're shown a couple of details that fill in his character: he has a Certificate of Bravery on his wall, so we extrapolate that he was a soldier who fought so valiantly that he was commended for his service (which the Doctor shortly thereafter confirms), and the Doctor implies that Quell's becoming an alcoholic, which suggests dark secrets in his past that he's trying to escape. I really appreciated that, while Quell does his duty and arrests the Doctor on suspicion of mystery-shopper impersonation ("I'm gonna have to mark you down for this!"), the next murder immediately makes Quell come to his senses and enlist the Doctor's help: "It turns out it's three. The amount of people that have to die before I stop looking the other way." Bamber is excellent, making Quell authoritative but not unreasonable, and balancing his gruff bravery with a dry sense of humor. I also really liked his delivery of "That was my best guard!" and "For the record, it didn't even flinch."

Even though the story isn't a traditional whodunit, so there's no need to cast suspicion on all of the characters, Perkins is introduced as a definite suspect for... something. When we first meet him, he's cradling a pipe as if he's ready to use it on the Doctor, with his face ominously hidden in shadow, and the Doctor clearly suspects that he's up to no good. As it turns out, Parker becomes one of the Doctor's staunchest allies, and the only person on the train who's eager to jump into the search, plus intelligent enough to ask clever questions and think of possible solutions. It's really no surprise, then, that the Doctor offers Perkins a permanent position on the TARDIS, helping repair the ship in between adventures. I can only assume that the production team never seriously intended to make such an offer, because I have a hard time imagining that Frank Skinner would have turned it down. Nevertheless, I'm tickled, as I'm sure he was, that his character made the cut. It's always a delight to see diehard fans win a role in the show, especially when it turns out to be such a heroic role as this was. I must say, I wouldn't have been at all disappointed if Perkins had become a new companion, because Skinner gives a fantastic performance. He makes Perkins capable, intelligent, mischievous, and cheeky to the point that you can't quite figure out at first if he's trustworthy or not. He also gives a number of excellent, interesting line readings, including "Well, I know that when I find a man fiddling with a chair that someone died in, it's best to play my cards close to my chest." and "No, sorry, Doctor, but I don't think I do." At least he gets a TARDIS scene (which has the side benefit of proving that the Doctor did not leave everyone to suffocate!).

Maisie Pitt (Daisy Beaumont) also benefits from Mathieson's script. She was clearly a child of privilege, but appears to have suffered emotional abuse throughout her childhood, what with her grandmother poisoning her pony and then forcing Maisie to accept her as a surrogate mother. One dreads to imagine what happened to her actual mother (most likely Mrs Pitt was her paternal grandmother, eh?). Clara's able to talk Maisie down from her hysteria, at which point Maisie becomes a valuable confidante for Clara, discussing her feelings about the events of Kill the Moon, and somewhat inadvertently helping her to realize that she isn't ready to leave the Doctor yet. And I love that Maisie gets around the need for a sonic screwdriver by jamming her high heel into the door controls! I liked Beaumont's delivery of "Computer, open the door!", "Not really meaning it. At least, I don't think I did.", "And thoughtless, and arrogant beyond belief!", "People do it all the time!", "That has to be a good thing, doesn't it, Clara?", and her horrified-slash-vindicated reaction to the Doctor's revelation that her pony really was poisoned.

Professor Moorhouse is perhaps the least successful of the main guest stars, but only because he doesn't get the same level of development as the others. It's practically required in a story of this type to feature at least one academic specialist, and Moorhouse fills the role perfectly well. His initial eagerness to meet one of the real-live monsters he's devoted his life to studying comes back to haunt him in this excellent line: "Actually, seeing it in the flesh isn't nearly as rewarding as I thought it might be." I also enjoyed Christopher Villiers' delivery of "How does it go?", and he gives a particularly good performance as he tries to answer the Doctor's questions while the mummy advances on him.

John Sessions is fantastic as the cheery automated voice of Gus: "We apologize for any distress you may have just experienced. Grief counselling is available on request. On the bright side, I'm sure you've all collected a lot of data! Well done, everyone!" Somewhere in the back of my mind, I knew that Mrs Pitt looked familiar when she summoned a waiter, but it wasn't until I learned Janet Henfrey was in the episode that the penny dropped. My goodness! What a delight to see her back in Doctor Who, even if the poor woman is typecast as a nasty shrewish domineering woman. She certainly continues to excel at the character type! This story is also notable for the casting of up-and-coming singer Foxes. I must admit, when they first announced her casting, I wasn't expecting it to be in the part of "lounge singer who belts out half a song in the opening scene only to completely disappear thereafter". Her rendition of Don't Stop Me Now isn't exactly my favorite (plus, hello — was "I'm a sex machine, ready to reload" really their best choice of lyrics to feature prominently on a family program?!), so all things considered, I'm not really sure why they made a special effort when her character was so peripheral to the plot.

The day that Mummy on the Orient Express aired, I was hanging out with my friend Shira from Chicago, giving her the grand tour of town while she was visiting for the weekend. I've known Shira since we were in high school, although we'd never actually met in person until almost exactly a year ago; she was one of my very first online friends, and we bonded over our shared love of Doctor Who. So of course the topic of Capaldi's Doctor came up, and Shira mentioned that the phrase "shut up" has become his Doctor's catchphrase. Well, you know that put me on my soapbox! And this week, yet again, we have two examples that I can't defend:

SHUT-UP COUNTER: 2 1.   (04:58)   Doctor: "Were people really confused? Cause I'm confused. What, did everybody leave?" Clara: "Oh, shut up."   2.   (45:16)   Clara: "Look, as long as you get me home safe, and on time, everything is great. I am so sorry, I've had a wobble, it's a big wobble, but it's fine. Forget about it. Now shut up and give me some planets."

Eight episodes in, and I'm ready to admit it: Murray Gold's music has been really impressive all season long. Maybe not always noteworthy in its brilliance, but never sub-par, and he's had several really strong episodes. This is one of them. The music this week combines an occasional hint of 1920s adventure serial with, in a clever move, themes that owe a direct debt to Agatha Christie adaptations from the 1990s, as when the Doctor and Clara go sneaking out of their rooms. It's extremely fitting, and suits the onscreen action perfectly.

Aside from the superb mummy, the effects that stood out to me were the freaky shot of the mummy's fingers coming through the Doctor's eyes, the very nice subtle effect of the light running under the Doctor's skin when he injects himself with Maisie's trauma, and the lovely shot of clouds drifting over the skyscrapers of the distant alien city. I also love the stylish design of Quell's gun.

Back for the second week in a row, Paul Wilmshurst's direction is again impressive. In a set as confined as the train interiors, Wilmshurst uses interesting angles, foregrounding and lighting to keep the shots interesting. The mummy, in particular, benefits from Wimshurst's use of angles, which emphasizes the mummy's face (or various other decaying body parts) while it reaches toward its victims. I really liked the panning shot from outside the train, of the mummy reaching toward Mrs Pitt; and the scene of the Doctor and Clara dematerializing the TARDIS together, although it's a shame the camera has to rocket around to get Clara's head in frame.

Minor points:

• As of this week, I think they've finally settled on exactly the right way to display the episode titles. They've been seesawing back and forth on whether or not to let them linger after the credits, and this solution — not only letting them linger, but slowly zooming in on them — finally allows the episode title and writer to make an impact, and gives the audience sufficient time to process them. Why did it take them eight episodes to figure this out? Here's hoping we won't revert to an earlier version next week.

• Mathieson shows his writing chops right from the start. I love when characters talk like real people would, and this line has the side benefit of reinforcing that the twelfth Doctor is not one for social niceties:

  Clara: "Do you know what the singer said?"
  Doctor: "Well, frankly, that would be an absolutely astonishing guess if I did know."

• Not a new question, as the Doctor points out, but by far the best answer he's ever given:

  Quell: "So, what are you a doctor of?"
  Doctor: "Now there's a question that's never asked often enough. Let's say... intestinal parasites."

• Killer writing. This is one of two lines that felt like the knife being twisted, and both Capaldi and Coleman absolutely sell it:

  Doctor: "To our last hurrah."
  Clara: (suddenly worried, and obviously having second thoughts) "Our last, yeah, but, I mean, it's not like I'm never gonna see you again."
  Doctor: "Isn't it?"
  Clara: "...is it?"
  Doctor: "I thought that's what you wanted."

• I love this line, because I have this exact same dialogue with myself every time I try to rate or grade something. (There's a reason why I prefer a holistic review to ranking stories out of ten!)

  Doctor: (to himself) "Really, 99 percent? That's quite high. Is that the figure you're sticking with? Okay, okay. 75. ...Well, that's jumping quite a bit. It just lost 24 percent."

• The number of evil is 33? Oh wait, I suppose "the number of evil twice over" means the first two numerals in 666. (Or 6 twice, but I didn't know that 6 was the number of evil either.) Okay, I sorta get it now.

• (Potential) Plot Issue #1: the Doctor says that there are rumors of a secret word that will prevent the Foretold from killing you. Given that this turns out to be true, we can assume it wasn't just wild speculation, which implies that it has been tested and proven at some point in the past. So why didn't the Foretold crumble to dust centuries ago? Or, given that no sources actually reported the exact safe words, was it wild speculation that just happened to be true? Alternatively, I can imagine a situation in which the enemy were told "our nasty mummy soldier will keep murdering you until you surrender!" and they never did, but this condition passed into legend as an unspecified safe word.

• I laughed out loud at the Doctor's cigarette case full of jelly babies! Now he's got a lemon one rattling around loose in there though. If I were him, I would've eaten that one.

• Oh, so many laugh-out-loud lines in this episode!

  Doctor: "I'm not a passenger. I'm your worst nightmare."
  Quell: (looking at the psychic paper) "A mystery shopper! Oh, great."
  Doctor: "Really? That's your worst — okay, I'm a mystery shopper. I could do with an extra pillow, and I'm very disappointed with your breakfast bar. And... all of the dying."

• I liked Perkins already, but this line — poking gentle fun at the conventions of mystery novels — made me really warm to him.

  Doctor: "Quick work, Perkins. Maybe too quick."
  Perkins: "Yes, sir. I'm obviously the mummy! ...or perhaps I was already looking into this."

• Jenna Coleman kills this line:

  Maisie: "Were the good times all like this?"
  Clara: "Yeah... now that you mention it..."

• So much good dialogue!

  Prof Moorhouse: "It's immortal, unstoppable. Unkillable."
  Perkins: "Could we get a new expert?"

• Is it a Wirrn???

  Clara: "Doctor, it's okay, it's, uh, it's full of... bubble wrap."

• (Definite) Plot Issue #2: "If I was putting together a team to analyze this thing, I'd pick you," says the Doctor. "And I think somebody has." This is a very creepy line, but the effect is somewhat undermined when we learn that the Orient Express is at least the third train that Gus has outfitted for analyzing the Foretold. So why wasn't Professor Moorhouse, the preeminent Foretold scholar, onboard the very first train? Is he maybe not the very most knowledgeable expert on the Foretold? Or was Gus trying to get some of the basic investigations out of the way before bringing in his big guns?

• (Potential) Plot Issue #3: I can easily forgive this because it helps build the atmosphere, but if Gus wants to extract as much information as possible before the Foretold sucks everyone's cellular energy, why does he wait to reveal himself until it's already killed three people? He could have locked down the train shortly after the journey started, and prepped everyone on their fate before the Foretold began its attacks. For that matter, why would Gus fill the passenger quota with holograms, which can't be killed, rather than ill people who could postpone the deaths of the researchers? And why kill off a whole carful of decoy victims just to stop the Doctor from finding out information that might advance their research? I suppose if Gus has already gone through at least two trains, maybe he has plenty more lined up, so he's not particularly bothered whether the Orient Express succeeds or fails. But it surely doesn't help Gus' cause when Professor Moorhouse is the fourth person killed.

• If the Foretold is bound to the scroll's physical location, you would think by now people would have made the connection and learned to stay well away from the scroll (if not destroy it outright). Which raises (Potential) Plot Issue #4: the Foretold appears to need to kill every few minutes, in order to prolong its life, so what happens if there's nobody in the scroll's vicinity for it to drain? Surely it should have expired long before now, unless it was cherished by a society that, say, fed all their hardened criminals to it as a form of corporal punishment.

• With only 5 seconds left to live, Professor Moorhouse is determined to find the secret word that will make the Foretold spare him. Assuming nobody else has ever thought of this one, he decides to give the traditional "magic word" a try: "Only please please please..." Well, if the first one didn't work, why waste your precious remaining seconds with two more?

• (Potential) Plot Issue #4: Where did Clara and Maisie find all of this information about the sarcophagus and passenger manifests? Was it just lying around inside the locked compartment? I suppose that makes sense, if Gus had sole control over the compartment, but then why would Quell have told Maisie that they'd put her mother's body there? Or was Maisie just incorrectly assuming that's where they'd stored it?

• (Potential) Plot Issue #5: If the sarcophagus is in a locked compartment in the baggage car, and all of the passengers are locked in one of the observation cars, then assuming they manage to capture the Foretold, how were they supposed to get it into the sarcophagus?

• (Potential) Plot Issue #6: If more than two other trains have been killed off already, did Gus make their research notes available to the current team? Obviously they discovered something of value, or else why was the Valiant Heart marked as "promising"? (And how did 38 people onboard manage to survive?) So you'd think that Gus would want to save this team the trouble of researching questions to which he already knows the answer. Yet when the Doctor theorizes that the Foretold's killings might not be random, Gus replies "Well done!" in a tone that implies it isn't new information.

• Quell says that Professor Moorhouse was suffering post-traumatic stress after a car accident. So they have cars in whatever time this is? Or maybe the word now refers to a different mode of transportation.

• (Definite) Plot Issue #7: The Foretold's method of choosing its victims is very unclear. It apparently selects its victims according to their general health. You'd think it would go after the healthiest first, on the assumption that they would extend its life longer, but instead it prefers to pick off the weakest first. So, in order, it kills people suffering from extreme age, a blood condition, lung implants, panic attacks, post-traumatic stress, then a nervous breakdown (or something). Why does it go after someone with lung implants who's otherwise in excellent health? Why do Moorhouse's panic attacks make him "less healthy" than Quell's post-traumatic stress? Why is a young woman who's doing a relatively good job of managing her grief and guilt targeted before several people who are at least 30 years older than she is? And, most importantly of all, shouldn't the Doctor be somewhere high up on the list? Why don't any of the simulations pinpoint him as the next most likely victim? Surely his post-traumatic stress is worse than Moorhouse's, unless he's been able to move past it after the events of The Day of the Doctor and his recent regeneration.

• (Potential) Plot Issue #8: Why does the Doctor assume that Quell is "probably next" before they know anything at all about the medical history of the rest of the passengers?

• (Potential) Plot Issue #9: The Doctor suggests that Quell back away from the mummy, to see if it teleports. Quell never moves, yet the mummy teleports anyway. Does it know where he's thinking of going?

• As the Doctor desperately tries to figure out anything about the Foretold, he appeals to the assembled experts for help. Apparently not a one of them has even a wisp of an idea to contribute, because they all just stare at him slack-jawed. Difficult to believe, but I guess that's the problem with non-speaking extras.

• (Potential) Plot Issue #10: If the Foretold leaches its victims' energy on a cellular level, why don't their bodies crumble to dust like the sacrifices in the Nimons' larder?

• (Definite) Plot Issue #11: If the mummy is out of phase, and therefore it needs to take its victims out of phase to drain their energy, how can the victims be seen by everyone else? Shouldn't they be gradually fading away, and become as invisible as the Foretold just before it touches them?

• Maisie must be very deep in thought or hard of hearing to avoid overhearing Clara's red-flag line "She's never gonna agree to this!"

• (Potential) Plot Issue #12: How do Clara and Maisie unlock the door to the baggage compartment? One minute they're hopelessly trapped, the next they're happily sauntering out. Did Gus unlock the door for them? Or maybe one of the crew with sufficient authority did it?

• (Definite) Plot Issue #13: How does the Doctor use a medical scanner to transfer Maisie's grief and resentment to his mind?

• Guffaw! Nice reference, Mathieson.

  Doctor: (to the Foretold) "I'm the Doctor, and I will be your victim this evening! Are you my mummy?"

• (Potential) Plot Issue #14, although it's so humorously scripted and delivered that I can easily let it slide. But otherwise: how does he know this? Did he somehow get her gran's memories too? Or is he just interpreting Maisie's memories through the lens of his own experience?

  Doctor: (to Maisie) "By the way, you weren't being paranoid. She really did poison your pony."

• (Definite) Plot Issue #15: How come Perkins is already fainting from lack of oxygen, but Clara can still form complete sentences with no evident signs of distress?

• Sure hope Gus had enough of an opportunity to scan that alien tech, 'cause it's 'sploded now. (Or the Doctor kept it!)

• Here's my other knife-twisting line. Capaldi slays this line as, yet again, the Doctor lets all the air out of what's threatening to become a sweet moment.

  Clara: "Is it like..."
  Doctor: "Like what?"
  Clara: "...an addiction?"
  Doctor: "Well, you can't really tell if something's an addiction till you try and give it up."
  Clara: "And you never have."
  Doctor: "Let me know how it goes."

So on close analysis, I have quite a few issues with the plot, but only a few that I genuinely can't explain, and none which seriously damage my ability to believe what's happening. It's just such an economically, entertainingly written script that I have to love it, and all the more because the set designers, costume designers and incidental music bring the fake 20s to vivid life. We've got a creepy monster that's worth building a story around, some interesting hints at a longer story arc, and increasingly fascinating developments in the Doctor and Clara's relationship. I'm glad to see the high quality of series 8 restored, and if next week's monster lives up to its potential from the trailer, I have no doubt that the trend is about to continue.