In this serial, the Doctor (Patrick Troughton) and his travelling companions Ben (Michael Craze) and Polly (Anneke Wills) arrive in the Scottish Highlands in 1746, just after the Battle of Culloden.
They gain the trust of the Jacobites, but their friendliness gets them into serious trouble with government troops led by Lieutenant Algernon Ffinch (Michael Elwyn).
They hide in a deserted cottage with the Laird Colin McLaren, who has been badly wounded, along with his daughter Kirsty, his piper Jamie McCrimmon and his son Alexander, who dies defending them from a patrol of government soldiers conducting mopping-up operations.
They hide in a cave, then an animal pit, from Ffinch, who believes Stewart to be one of them following the rumour that he fled the battlefield as a woman.
Grey is freed by Trask, who reports that the transportation plan has begun and arranges for a number of prisoners, including Jamie, Ben and the Laird, to be transferred to Annabelle.
The ruse works, distracting Grey and Trask while Polly and Kirsty free the Jacobite prisoners and supply them with weapons for an uprising.
Willie Mackay takes control of Annabelle and plans to sail her to freedom in France, accepting Perkins as a volunteer for this journey along with Kirsty and Colin.
The Doctor, Ben and Polly return to the town, using Grey as a hostage to ensure their freedom of movement, and are joined by Jamie, who has decided to stay and help them find the TARDIS.
Ffinch arrests Grey for the transportation scheme, as he has lost the paperwork thanks to the Doctor and is unable to prove the legality of his plans.
[3] Patrick Troughton encouraged the move away from historical stories, according to his son Michael, out of an interest in exploring "real science in drama" as well as a desire to further distinguish his era from that of the previous Doctor, William Hartnell.
He was also mildly critical of "pantomime and cliché" in the serial, in particular Patrick Troughton's use of silly voices and unconvincing disguises.
As with all missing episodes of Doctor Who, full off-air audio recordings exist due to contemporary fan efforts.