The TARDIS lands in a forest clearing.  The travelers think it's England in 1963 but they are in fact 20 kilometers from Paris during Robespierre's Reign of Terror in 1794.  A farmhouse is sacked by Government troops; the Doctor is concussed and left for dead, the others are dragged of to prison. After first being captured by Royalists and then by Citizen soldiers. Ian eventually meets up with the others Ian is given vital British intelligence by a dying cell mate, and escapes from the prison, while Barbara and Susan are rescued en route to the guillotine. The Doctor masquerades as a civil dignitary, while Ian gets involved in the counter-revolutionary plot of English master spy James Stirling.  Ian and Barbara journey to an inn for a clandestine meeting with Barrass, Robespierre's deputy and Napoleon Bonaparte, who are plotting the tyrant's downfall. Ian and Barbara report back to Stirling, who is intrigued that Bonaparte could be the next ruler of  France. Events reach there climax, Robespierre is overthrown as the Doctor and his companions slip away.




The Doctor: William Hartnell
Ian Chesterton: William Russell
Barbara Wright: Jacqueline Hill
Susan Foreman: Carole Ann Ford

Guest Appearances:
Robespierre: Keith
Rouvray: Laidlaw Dalling
d' Argenson: Neville Smith
Jean: Roy Herrick
Danielle: Caroline Hunt
Colbert: Edward Brayshaw
Judge:  Howard Charlton
Jailer: Jack Cunningham
Webster: Jeffrey Wickham
Overseer: Dallas Cavell
Bonaparte: Tony Wall
Lemaitre/Stirling: James Caincross
Small Boy: Peter Walker
Sergeant: Robert Hunter
Barrass: John Law

Producer:  Verity Lambert
Assistant Producer: Mervyn Pinfield
Script Editor:  David Whitaker.
Writer:  Dennis Spooner.
Director:  Henry Hirsch, (episode 3, uncredited directed by John Gorrie) 
Designer:  Raymond P. Cusick
Costume: Daphne Dare
Make up: Jill Summers
Music: Norman Kay

a
Novelized as "Doctor Who - The Reign
of Terror by Ian Marter (0 426 20264 3) first published by W.H. Allen (now Virgin Publishing Ltd) in 1987 with cover by Tony Masero.  Target library number 119.

Full release not available due to the loss of the story. A release of the four remaining episodes was contemplated in the 1990's by the BBC, and an introduction to the story was taped featuring Carole Ann Ford (Susan), but this was eventually discarded and the release scrapped.

.

.

This serial was a replacement for a canceled 6-part story by David Whitaker concerning the aftermath of the Spanish Armada; the idea for a French Revolution story was suggested by cast member William Russell.
Carole Ann Ford taped a segment to introduce and bridge the planned video release of this story, but the release was canceled.
The first ever on-location filming was done in this story, with a second-unit taping a body double for William Hartnell in the countryside.
William Russell appeared in "Guests of Madame Guillotine" and "A Change of Identity" only in pre-taped inserts, as the actor was on holiday during the taping of these episodes.

Episodes 1, 2, 3 and 6 exist on 16mm telerecordings. Episode 6 was returned by a private collector in May 1982; prints of all four extant episodes were recovered from a television station in Cyprus circa 1985 (including a superior print of episode 2). Twelve clips from episodes 4 and 5 exist in the form of an 8mm home movie reel shot off a television set.

Ealing Filming. (16-18 June 1964)
Studio recording in TC4. (7, 14 August 1964)
Studio recording in Lime Grove D. (10, 17, 24, 31 July 1964)
Isle of Wight Farm, Over the Misbourne Road, Gerrards Cross, Buckinghamshire. (15 June 1964)
White Plains, Tilehouse Lane, Denham Green, Buckinghamshire. (15 June 1964)

Episode 3 - During the gunfight to rescue Susan and Barbara from the wagon taking them to be guillotined, one soldier is seen kneeling by a wheel (on the right of the screen) - then in the next frame, he's suddenly standing up.
Episode ? - Jules Renan claims that the collaborators on the escape line are on a first-name basis only, but later he casually refers to two of them as Rouvray and D'Argenson.