The Doctor and Jo are being held prisoner by Axos while Chinn is forced to organise the worldwide distribution of axonite and the Master returns to the power complex to try and steal the TARDIS.

The Time Lords takes control of the TARDIS and the Doctor and Jo arrive on a Earth Colony in the 25th Century, where a ruthless mining company are using a dinosaur-like creature to force the colonists to leave the planet. Where the Doctor and Jo learn that The Master is on the planet and is in search of a doomsday weapon that is hidden somewhere on the planet.