Continued from the previous episode. Because Morbius is being revived, Straxus was sent to retrieve the Eighth Doctor and all other off-planet Time Lords to prevent that from happening, and the Sisters of the Flame were meddling appropriately. When Zarodnix gets his hands on Straxus, though, he decides that one Time Lord is as good as any other, and Morbius is revived using Straxus' cells.
Lucie and the Doctor eventually decide to ignore all the rules of time and cross their own timelines to prevent all that. They screw up magnificently and end up ten years into the future — whole galaxies have been destroyed, Earth is a slave planet, Straxus is still being harvested for cells, and Rosto is brainwashed but desparately clinging to his memory of Lucie. The Sisters of the Flame are helpless to prevent anything, and now only hope that Morbius' stellar manipulator activator can be retrieved.
The Doctor establishes a psychic link to the Sisterhood and begs them to save the universe. They ignore him, and the Doctor has no choice but to plunge himself into the abyss where Morbius first died, carrying Morbius with him and killing him a second time. This resets the timeline, and the ten years of war never happened.
With the Doctor now dead, the Time Lords offer to wipe Lucie's mind to ease her grief, but she asks them to just drop her off back home in Blackpool and let her mourn the Doctor in peace.
A lot of this episode becomes Harsher in Hindsight after "The Night of the Doctor".
- Bad Future: The future where Morbius has conquered entire systems.
- The Dog Bites Back: After at least ten years of being controlled by Morbius, Rosto is able to fight Morbius.
- The Emperor: Morbius.
- Mind-Control Device: Zarodnix and Morbius use the Trell like this.
- Life Drinker: Morbius survives by "feeding" on Straxus, using his genes.
- Pet the Dog: Straxus telling Lucie is sorry at the Doctor's death.
- Shout-Out: The Doctor and Morbius plunging to their deaths while fighting is this to Sherlock's (apparent) and Moriarty's death in "The Final Problem".
- The Stinger: The Headhunter shooting Lucie Miller.