The Eighth Doctor's journey to recover his other incarnations begins. The Ninth Doctor finds himself locked up on the prison planet Inferno 161, and his cell mate Cigam warns him that escape is impossible.
With Cigam in control of the TARDIS, The Eighth Doctor is trapped on Inferno 161, but he is not alone. Meanwhile on board the TARDIS, Maria begins a fight for her life that will end with a revelation about her very being.
Whilst the Eighth Doctor searches the universe for his lost incarnations, the Sixth Doctor faces upgrading at the hands of the Cybermen, but help may be closer than he thinks.
With the aid of a new ally, the Sixth Doctor attempts to thwart the Cybermen's invasion plans. Soon, however, the Sixth Doctor becomes a hunted man, targeted for death.
The Sixth Doctor and his new ally put their bold strategy into action, but the Cyber Controller stands in their way, as does a far more unexpected foe.
The Second and Eighth Doctors are on the run, whilst Maria falls prey to the asylum's sinister Director, who will stop at nothing to gain what he seeks...
The Fourth Doctor attempts to diffuse a rocket warhead in the midst of a bloody rebellion on an Earth colony, but he remains unaware of the rocket's true, darker purpose.
The Fourth Doctor and Maria take refuge in the war-torn ruins as Earth soldiers and rebels - now united with a single mission - capture the Eighth Doctor as a prisoner of war.
The Fourth and Eighth Doctors find themselves trapped as their enemies close in. Will they risk the death of all their incarnations, or surrender their most vital asset.
The Fifth Doctor bargains with an alien merchant in hopes of finding his lost TARDIS, but instead discovers the merchant is selling the deadliest substance in the universe.
The Fifth and Eighth Doctors combine forces to do battle with a toxic menace that threatens to destroy the galaxy, yet their victory could lead to a far greater defeat.
The First Doctor and Erasmus explore the mysterious tunnels inside the asteroid, as the Eighth Doctor and Maria find themselves surrounded by the Cyber Fleet.
The Cyber Fleet launches an all-out assault on the asteroid as the First and Eighth Doctors defend themselves, whilst Maria faces the Cyber Conglomerate.
The Eighth Doctor battles the Cyber Controller as the Seventh Doctor struggles against the Cyber Conglomerate, and Maria must choose which Doctor to save.
Using the Doctor's own life force, Omega travels back into Gallifrey's past to stop himself from making Time Lord history - but at what cost for both the Doctor and the planet?