Dec 9, 2021
The Doctor runs from Swarm, taking Tecteun's Ood with her. Swarm and Azure advance on her but the Doctor takes off her conversion plate and, as Swarm touches her, is split into three copies between the Division spacecraft, Karvanista's ship, and the Liverpool tunnels.
On the Division spacecraft, Azure attempts to return the Doctor's missing memories to her using the fob watch. The Doctor refuses to see them. Azure reveals her intent to engineer the Flux into a time loop of universal destruction. The Ood attempts to slow down the Flux.
In the Passenger, Vinder and Diane disrupt its internal systems and escape into another unknown environment.
Yaz, Dan, Jericho, and Williamson take out the Sontaran vanguard with lightning from a tunnel door before traveling to 2021 through another. They meet Kate Stewart who is leading a resistance against the invasion. The Doctor bargains for Claire and Jericho to help them find the final Flux event's coordinates. She takes her TARDIS from Kate.
The Doctor crashes Bel's ship into the Sontaran command headquarters. They are stopped by a force field, captured, and placed on a Sontaran ship. Karvanista reveals that during the Doctor's time in the Division, he was her companion. He cannot say more about it, under threat of a Division poison implant in his brain. The Sontarans remove the Doctor and inform Karvanista of the Lupari's extinction.
The Doctor piloting the TARDIS frees her copy from the Grand Serpent's torture device and aims it at him.
Bel downloads Sontaran transmissions offering alliance with the Cybermen and Daleks, a ruse to sacrifice them to the Flux while the Lupari shield ensconces the Sontarans. Claire escapes the ship. Jericho cannot. The Doctor rescues Vinder and Diane, and reforms the Lupari shield behind the Sontarans, leaving the Flux to consume the Sontarans, Jericho, Daleks and Cybermen. The Doctor uses the Passenger, a repository of endless matter, to absorb the Flux.
Azure and Swarm bring the Doctor to Atropos to sacrifice her to Time, but since the Flux failed to free Time, Time destroys them. Time lets the Doctor go but warns of her end before reunifying her. In the tunnels, Kate and Vinder maroon the Serpent on a small asteroid through a door. Vinder and Bel decide to travel with Karvanista. Dan invites Diane on a date, but Diane refuses. The Doctor invites Dan to join her and Yaz on their travels. She deposits her fob watch deep into the TARDIS interior.