Written by Chris Chibnall
"The end of the Universe. I always wondered what it would feel like."
| Episode Title | Premiere Date |
| Chapter One: The Halloween Apocalypse | 31/10/2021 |
On Halloween, all across the universe, terrifying forces are stirring. From the Arctic Circle to deep space, an ancient evil is breaking free. And in present-day Liverpool, the life of Dan Lewis is about to change forever. Why is the Doctor on the trail of the fearsome Karvanista? And what is the Flux?
| Character | Cast |
| The Doctor | Jodie Whittaker |
| Yasmin Khan | Mandip Gill |
| Dan Lewis | John Bishop |
| Karvanista | Craige Els |
| Joseph Williamson | Steve Oram |
| Diane | Nadia Albina |
| Swarm | Sam Spruell |
| Azure / Anna | Rochenda Dandall |
| Vinder | Jacob Anderson |
| Claire | Annabel Scholey |
| Ritskaw | Jonathan Watson |
| Kragar | Dan Starkey |
| Old Swarm | Matthew Needham |
| En Sentac | Sarah Amankwah |
| K-Toscs | Charlie Oscar |
| Wilder | Richard Tate |
| James Stonehouse | Paul Leonard |
| Wilma | Heather Bleasdale |
| Kev | John May |
| Jon | Gunnar Cauthery |
| Weeping Angel | Barbara Fadden |
| Role | Crew |
| Writer | Chris Chibnall |
| Director | Jamie Magnus Stone |
| Executive Producer | Chris Chibnall |
| Executive Producer | Nikki Wilson |
| Executive Producer | Matt Strevens |
