Bernard Kay

Monk tries to run down how someone could be in two places at the same time after a woman is found murdered during a citywide marathon race.

The Master offers to assist the colonists in exchange for information and forces the Doctor to show him the way to the Primitive City.

The Master and the Doctor are taken to the Primitive city; the Master seeks to find the doomsday weapon; Dent forces the colonists to leave the planet.

The Doctor discovers too much about the mining schemes of Captain Dent and is marked for death; a robot attacks the Doctor.

The Doctor discovers a doomsday machine left by a highly advanced civilisation; the Master arrives on the planet.

When Jo attempts to break into the IMC ship to find damning evidence, she is captured and held hostage. If the Doctor doesn't cooperate, Captain Dent will have Jo killed.