The TARDIS is still unable to return to 24 May 2025 on Earth, so the Doctor (Ncuti Gatwa) and Belinda Chandra (Narada Sethu) end up 500,000 years in the future, where a group of Troopers led by Shaya Costallion (Caoilefionn Dunne) is investigating the loss of contact with a mining colony. Everyone has been murdered except for Aliss Fenly (Rose Ayling-Ellis), a deaf cook who tells them the whole team went mad and started killing each other. The Doctor notices that every mirror on the base is broken.
Belinda learns that Aliss and the troopers have no knowledge of Earth, and the Doctor realizes he has visited this planet before, which was called Midnight at the time, about 400,000 years before. One of the Troopers moves behind Aliss and dies. Aliss says there is an entity hiding behind her, which the Doctor also knows about. Aliss says that the entity will transfer to anyone who kills her.
Trooper Casio Palin-Paleen (Christopher Chung) frustrated by Shaya’s lack of action, relieves her of command and his own efforts cause the death of many troopers. Shaya gets Cassio killed by having Aliss turn her back on him. The Doctor tries to communicate with the Midnight entity and there seems to be some contact. He thinks the entity is afraid of its own reflection and so he has Shaya shoot the pipes containing the mined mercury, creating a liquid mirror that frees Aliss.
They then attempt to escape the colony. Aliss and two troopers leave first, but the entity latches on to Belinda. To free her, Shaya shoots her in such a way that she can be revived later. The entity seems to transfer to Shaya, who sacrifices herself. Belinda and the Doctor leave in the TARDIS.
On a spaceship, soldier Mo Gilliben (Bethany Antonia) reports the events to Mrs. Flood (Anita Dobson), whom we have seen before. A trooper notices something behind Mo.
The episode was co-written by Russell T. Davies and Sharma Angel-Walfall, and directed by Amanda Brotchie. Aliss is portrayed by Rose Ayling-Ellis, a deaf actress. The cast was trained in British Sign Language. The episode is a sequel to the 2008 episode “Midnight”. Much of it was inspired by a story Angel-Walfall had written. The actors who played Troopers were sent to boot-camp. The spacesuits were problematic and there was a lot of wire-work required. It was generally well-received, though the entity was criticized as not as frightening as its first appearance.
I thought the episode was particularly creepy as the invisible creature terrified the characters and they began to suspect and fear each other like those in The Thing movies, both the 1951 original in the Fifties and John Carpenter’s 1982 sequel.