A companion switch, far too many people in shorts, and the Brotherhood of Sarn
The cast of Monty Python’s Life of Brian seem to be shacked up with Laurence of Arabia on a desert planet called Sarn. Being the backwater world that Classic Who likes to frequent, Sarn of course has an elder / soothsayer, a chosen one sporting a fancy 3D tattoo, and some heretics who refuse to worship the fire god, Logar.
At the not-same time and not-same place, an artefact with a symbol matching the chosen one’s tattoo is discovered by Indiana Jones wannabes in modern day Lanzarote. And look who’s tagging along to their archaeological expedition, why it’s none other than future companion Peri, who’s a bit bored and longing to travel. Oh, what’s that you say? The TARDIS is about to appear and whisk her away on an adventure. Spiffing!