Sarah is ambushed by a Zygon

Tags: Fourth Doctor, The Brigadier, Harry Sullivan, Sarah Jane Smith, Zygons

Terror of the Zygons, episode 1
30 August 1975

The Brigadier calls the Doctor back to Earth. Something has been destroying oil rigs in the North Sea. Harry finds a survivor on the beach, only to be picked off by a sniper. As the Doctor tries to work out what's destroying the rigs, Sarah stays by Harry's bedside...