The Doctor: Ncuti Gatwa
Companion: Varada Sethu – Belinda Chandra
Others
Annabel Brook – Hanno Yeft
Luke Rhodri – Callo Rence
Bethany Antonia – Mo Gilliben
Gaz Choudhry – Kai Sabba
Christopher Chung – Cassio Palin-Paleen
Caoilfhionn Dunne – Shaya Costallion
Gary Pillai – Albie Bethick
Rose Ayling-Ellis – Aliss Fenly
Frankie Lipman – Sal Van Hyten
Paul Kasey – It Has No Name
Jermaine Dominique – Ulric Dazen
Anita Dobson – Mrs Flood
Amy Tyger – Val Vivo
Directed by Amanda Brotchie
Written by Russell T Davies, Sharma Angel-Walfall
Produced by Chris May
Executive producer(s): Russell T Davies, Julie Gardner, Jane Tranter, Joel Collins, Phil Collinson
Music by Murray Gold
Series 15
First broadcast 26 April 2025
Still unable to return to Earth on 24 May 2025, the Doctor and Belinda Chandra land the TARDIS on a spaceship 500,000 years in the future. They emerge amongst a group of troopers, led by Shaya Costallion, where they are immediately included in an orbital drop onto a planet. On the surface, they discover that the group are investigating the lack of contact from a mining colony. They find all the colonists murdered except for Aliss Fenly, a deaf cook. Aliss claims she was forced to murder her nearby friend, who went mad and attacked her. While Belinda and most of the troopers stay with Aliss, the Doctor goes with Shaya to the colony's control centre. There, he sees a vast well that was the mining operation centred upon. The Doctor and Belinda separately learn that the troopers and colonists have no knowledge of Earth or the human race.
The Doctor investigates the final video recorded by the colonists, which suggests something emerged from the well. Shaya tells him that the planet was formerly known as Midnight, and he realises that he has encountered a mysterious creature on the planet before.[a] Meanwhile, Belinda briefly thinks she sees something behind Aliss, but none of the group can see anything on further investigation. When a trooper moves behind Aliss, she is thrown across the room to her death. The Doctor and Shaya return to the group and Belinda theorises that an entity is concealed behind Aliss, and anyone who moves behind that entity – at the point of midnight on a clock face where Aliss is the centre – is killed. Aliss confirms that the entity will transfer to anyone who kills her. Trooper Cassio Palin-Paleen, frustrated by Shaya's lack of action, relieves her of command and moves behind Aliss to take offensive action. As Aliss turns to face Cassio, multiple troopers are killed when they are behind her back; Shaya eventually takes control and asks Allis to turn around, killing Cassio.
The Doctor attempts to communicate with the entity, and the two appear to acknowledge each other. The Doctor theorises that causing a mercury leak behind Aliss will force the entity to confront itself, at which point Aliss is freed. The group attempts to escape the colony. Aliss and two troopers leave first, though unnoticed by the others the airlock shows four lifesigns. Before they can can follow the Doctor, Belinda, Shaya and trooper Mo Gilliben realise the entity is behind Belinda. Shaya shoots Belinda in a precise position to allow her to be revived, seemingly causing the entity to transfer to her, before running through the colony and diving into the well.
Belinda is revived in the TARDIS, where she and the Doctor share their concern that the Earth is unknown in this future. Meanwhile on the mothership Mo reports the events of the expedition to Mrs Flood, before she and another trooper responds to the sound of the TARDIS dematerialising. Finding nothing Mo instead sees the other trooper staring over her shoulder, and begins to look fearful.
The Well