The Galois Group (audio story)

The Galois Group was the sixth and final story of Volume 12 of Big Finish Productions' Short Trips series. It was written by Felicia Barker and featured the Eleventh Doctor and Valarie.

Publisher's summary
There are rules to travelling in time, rules that Valarie Lockwood thought she understood. But, when she has an opportunity to break those rules, she seizes the chance. Valarie's going to have to learn the hard way that the laws of time are there for a reason.

Plot
An hour after an argument and subsequent reconciliation over the Web of Time, the TARDIS falls into what the Doctor describes to Valarie as a temporal pothole. They find that they have landed in the attic of mathematician Évariste Galois on 29 May 1832, the day before he is shot in a duel. Valarie suggests that they distract the opponent, but the Doctor reminds her that some things have to happen.

Walking around outside, Valarie falls through a rift and arrives in Sainte-Pélagie Prison in 1830, where Galois has been imprisoned after twice threatening King Louis Philippe with a dagger. She takes Galois with her through the rift to keep him from being killed in 1832 and confesses to the Doctor what she has done. He realises that Galois is the paradox that caused the TARDIS to land here and sends him back through the rift, with Valarie accompanying Galois per his request.

Back in 1830, Valarie and Galois see two ghostly versions of Galois: one Galois who never met Valarie and the Galois who would go through the rift with her. The TARDIS materialises and the Doctor and another Valarie join them, noticing that the Galois who came with Valarie has now split into one who sees them and a ghostly one who continues as though they had not arrived. The Doctor and the other Valarie explain that they landed here because of the temporal disruption and that they have not been to 1832, after which the other Valarie becomes a ghost as well.

The Doctor gives Valarie TARDIS calibrations to take to the Doctor in 1832, planning on having both their TARDISes pass through either end of the rift. The plan works and the aberrant versions of everybody disappears, meaning that this version of Valarie disappears. An hour after her argument with the Doctor about the Web of Time, Valarie, with no proper memory of the adventure, asks to meet Galois in 1832 despite being unsure of how she had heard of him. She visits him in the hospital to be with him before he dies.

Characters

 * Eleventh Doctor
 * Valarie Lockwood
 * Évariste Galois

Worldbuilding

 * The Doctor mentions Galois theory and Galois groups.
 * The Doctor mentions the Blinovitch Limitation Effect.
 * Galois' father was a mayor and poet. He was driven away by hateful letters written by a cleric and committed suicide.

Continuity

 * The TARDIS has been being menaced by a mystery caller who almost destroyed it. (AUDIO: The Inheritance, The End)
 * The Doctor and Valarie have been arguing about changing time. (AUDIO: All of Time and Space)
 * Valarie remembers the time spiders. (AUDIO: The End)
 * Valarie tells Galois about how she lost her mother. (AUDIO: The Inheritance)