The TARDIS lands on Earth six years out of date, stranding the Doctor in 1983 while leaving Tegan and Nyssa to look for him in 1977, eventually to discover a badly injured man that may very well be the Doctor. Both parties also encounter former Doctor-companion Brigadier Lethbridge-Stewart, though in 1983 he curiously has no memory of the Doctor at all.
Did You Know?
This episode was watched by 7.5 million viewers on its original transmission. See more
I've lost my TARDIS; you've lost your memory. I'd be surprised if the two events weren't connected.
Brigadier Alistair Gordon Lethbridge Stewart
Let me tell you, sir, that I'm in full possession of all my faculties. After all, if I was suffering from amnesia I'd be the first to know about it, wouldn't I?