Parts: 1 (45-minute)
Writer: Gareth Roberts
Airdate: 17 May 2008
Production Code: n/a

Doctor: tenth
Companion: Donna

Creature Feature: Vespiform

Story: December 8, 1926: the TARDIS materializes on the grounds of a manor owned by Lady Clemency Eddison, on the afternoon of a grand dinner party for some visiting dignitaries. Donna is thrilled by the idea of going to a posh 1920s party, and soon finds an appropriate flapper dress from the TARDIS' wardrobe. While having drinks on the grounds, Lady Eddison introduces them to the guests of honor: Robina Redmond, famous young London socialite... and acclaimed writer of detective fiction Agatha Christie. Donna is floored to be introduced to the murder-mystery author, but the Doctor recognizes something more sinister afoot: the eighth of December is the day that Agatha Christie, having just discovered her husband's affair, vanishes for ten days, with no memory of the interim when she reappears at a hotel in Harrogate.

Even stranger, the party mood is dashed when the housekeeper discovers the body of one of the guests, murdered, in the library. Immediately, the Doctor and Agatha Christie set about looking for clues and interrogating the partygoers, but as more murders occur, Donna begins to wonder: why is Agatha being surrounded by murders straight out of her books, when that sort of thing never happened to her in real life? And as she investigates the upstairs bedrooms, Donna comes across a much bigger clue than she had expected: a giant — as in flippin' enormous — murderous wasp...