This is a bit of a cheat. I’ve got a cold. I’ll try to do something more complicated next week. Unless I don’t. So very tired.
3×08 Rise of the Cybermen: Part One of Two. Now that Colin knows about his condition, the Doctor takes him to a dangerous part of the vortex in search of a cure. Instead, the TARDIS is stranded in a parallel universe where Colin’s father is still alive, Sammy meets her doppleganger, and one of the Doctor’s oldest foes is about to be reborn.