The Witch Hunters
Roots: The Salem Witch Trials, obviously: Lyons cites various references that he used for research, including Arthur Miller's The Crucible, Francis Hills' A Delusion of Satan, Chadwick Hansen's Witchcraft at Salem, and Marion L. Starkey's The Devil in Massachusetts. There is a reference to Winston Churchill.
Dialogue Triumphs: "Sometimes, Miss Wright, I think there is no period of your history that isn't awash with the blood of innocents."
"It is far better to let the guilty go unpunished than to make the innocent suffer."
Continuity: The Doctor briefly plans to leave his companions, including Susan, in Salem Village whilst he moves the TARDIS into the Vortex for a month to give it a complete overhaul; when he gets found out, all three of them talk him out of it and persuade him to effect repairs on Earth whilst they stay for a few days in the village. The Doctor is inspired to adopt the alias Doctor John Smith by his recollection of Susan's interest in the band John Smith and the Common Men (An Unearthly Child). He changes history by arranging a pardon for Rebecca Nurse, thus breaking a vow never to interfere in history. The Doctor makes a fourth and final visit to Salem Village after the events of The Five Doctors, a favour granted to him by Rassilon, and takes Rebecca Nurse on a series of short trips through time to show her how the future remembers her, before returning her to 1692 to face her execution. He forges a set of papers bearing the seal of Governor Phips. He uses the alias Benjamin Jackson, suggesting that The Five Doctors takes place between The Smugglers and The Tenth Planet.
Susan doesn't believe in magic. She wears a fur-hooded cloak. She isn't convinced that it is impossible to change history, and the Doctor notes that she might learn about four-dimensional physics when she's older, implying that she hasn't yet. The Doctor hasn't taught her how to fly the Ship, so she can't pilot it on her own. The Doctor suspects that she will leave him soon. Susan's telepathic abilities (The Sensorites) make her susceptible to the hysteria in evidence in Salem Village, causing her to have fits and hallucinations until she manages to erect psychic barriers.
Barbara poses as Barbara Chesterton whilst in Salem Village, thus pretending to be Ian's wife; Susan adopts the alias Susan Chesterton, their daughter. The three of them stay at Ingersoll's tavern and pretend to be from Boston. In 1954, Barbara was a student teacher in Cricklewood, living in a rented room. Barbara's failure to save the Aztecs still hurts (The Aztecs). She is accused of witchcraft in Salem Village and forced to flee.
Ian isn't religious. He left unmarked homework in his car in Totter's Lane when he and Barbara first stepped on board the TARDIS. Accused of being a warlock, he is arrested and imprisoned whilst in Salem Village, where he is interrogated, chained, and at one point stripped so that his captors can search for a "witch's tit".
The TARDIS' image translator needs adjusting, meaning that the scanner shows nothing but a blank screen. The Doctor has repaired the fast return switch since the events of The Edge of Destruction, but disables it after Susan uses it to return to Salem Village. Barbara finds a book on the Salem witch trials in the TARDIS library.
Links: This story takes place between The Reign of Terror and Planet of Giants. There are references to The Five Doctors. Abigail predicts that Susan will marry a fighting man, which she does after The Dalek Invasion of Earth. There are references to the fast return switch (The Edge of Destruction), the fluid links, Daleks and Skaro (The Daleks), the fault locator (The Daleks, The Edge of Destruction), Marinus and the Voord (The Keys of Marinus), the Sense-Sphere (The Sensorites), and Ian and Barbara's experiences of the French Revolution (The Reign of Terror). Barbara recalls the Doctor's claim that it is impossible to alter history (The Aztecs).
Location: Salem Village, Massachusetts, 11th to 16th January and 29th to 19th July, 1692, and 14th January 1693; Bristol, England, 9th November, 1952; and an unknown location on Earth, 8th September, 1742.
The Bottom Line: "They will always remember what happened in Salem Village." An exercise in emotional button pushing by exploiting the inherent injustices of its setting, The Witch Hunters is obvious and therefore overrated. Nevertheless, it's a solidly written and undeniably moving novel, reinforcing the theory that it's hard to go wrong with Hartnell historicals.