Parts: 1 (45-minute)
Writers: Pete McTighe and Chris Chibnall
Airdate: 02 February 2020
Production Code: n/a

Doctors: thirteenth
Companions: Ryan, Yaz, Graham

Creature Feature: Praxeus

Story: When the TARDIS flags multiple alerts across the Earth, the Doctor dispatches her companions to investigate. Ryan heads to Peru, where a pair of vloggers have encountered a flock of birds, all behaving strangely and apparently ill. In Hong Kong, Yaz and Graham track down a mysterious signal, where they team up with an ex-cop on a missing persons case. And in Madagascar, near a ramshackle oceanside microbiology lab experimenting with water filtration, the Doctor rescues a nearly-drowned submarine officer on the beach.

What could possibly connect all of these disparate events? The Doctor will have to investigate quickly, because innocent people are about to start dying...