Doctor Who (1963)

S20E10 Mawdryn Undead (2)

The TARDIS touches down on Earth, but it's six years behind the times, leaving the Doctor stuck in 1983 while Tegan and Nyssa search for him in 1977. During their separate adventures, both groups run into the former companion Brigadier Lethbridge-Stewart, who surprisingly seems to have forgotten all about the Doctor.