The Sacrifice of Jo Grant (audio story)

 was the third story in the audio anthology The Legacy of Time, produced by Big Finish Productions. It was written by Guy Adams and featured Tim Treloar as the Third Doctor, Katy Manning as Jo Jones, Jemma Redgrave as Kate Stewart and Ingrid Oliver as Osgood.

Publisher's summary
When pockets of temporal instability appear in a Dorset village, UNIT are called in. Soon, Kate Stewart and Jo Jones find themselves working alongside the Third Doctor, while Osgood battles to get them home. But this isn't the first time UNIT has faced this threat. Only before, it seems that Jo Grant didn't survive...

Plot
Jo and Osgood are interrupted at a swimming pool by Kate and, on a UNIT aeroplane, are informed of pockets of temporal instability on the coast near Wychert, Dorset. The same thing happened in the same place during the Winspit Incident in the 1970s and, according to a report by Allison Williams, was resolved not by the Third Doctor but by the death of Jo, who has no memory of the incident. A group of people from the 16th century have already been brought to the 21st century and are being kept sedated pending relocation.

Upon arriving at the beach, Kate is pulled into one of the holes and Jo goes after her. They encounter the Doctor, when Osgood makes radio contact, he tells Osgood that he will get Jo and Kate home and close the holes. In the 2010s, a waveform bores holes in reality and restores a pliosaur which eats one of Lieutenant Wallace's men before returning to bones, the waveform heading towards the village. Looking for the oldest place there, Osgood and Wallace go to the church and the waveform animates a Brontosaurus and the oldest skeletons in the graveyard. Osgood puts a time flow analog together and uses it to remove the waveform's control.

The Doctor puts together a machine to safely close the holes within four or five hours and explains that Jo and Kate will have twenty seconds just before they close to return home. He tasks Kate with calling the Brigadier to inquire about soldiers, but she is wary of doing so and escapes having to do so when the soldiers arrive. Jo advises her to speak with the Brigadier at some point before they leave and, remembering Allison's report, suggests that she will sacrifice herself to close the holes sooner than the four or five hours. Whilst the Doctor and Jo have lunch, Kate receives contact from Osgood, telling her to alter the Doctor's machinery.

Kate's alterations have caused time to behave chaotically and she brings the Doctor and Jo back to the beach. The Doctor believes that somebody might have impersonated Osgood and works to repair the damage, planning on risking his life to pass through one of the holes with a device. He refuses to let Kate take his place, having worked out that she is the Brigadier's daughter, and advises her to make contact with her father. Whilst she does so, Allison arrives and Jo knocks the Doctor out with Venusian aikido to take his place. Jo passes through the hole and finds herself outside of time until Kate saves her and hands her a letter from the Doctor; in it, he explains that he invented a gadget to rescue her and ensured that it ended up with Osgood.

Cast

 * The Doctor - Tim Treloar
 * Jo Jones - Katy Manning
 * Kate Stewart - Jemma Redgrave
 * Osgood - Ingrid Oliver
 * Lieutenant Wallace - Nicholas Briggs
 * Allison Williams - Karen Gledhill
 * Brigadier Lethbridge-Stewart - Jon Culshaw

Uncredited cast

 * Pirate - Nicholas Briggs

Continuity

 * When Kate says that the incident happened during her first year at UNIT, Jo replies she would probably be stuck at HQ, going through "reported sightings of ". (TV: Colony in Space)
 * Jo accidentally tells the Doctor that his exile on Earth will eventually be rescinded. (TV: The Three Doctors)
 * Jo reveals to the Doctor that she has seven children and thirteen grandchildren. (TV: Death of the Doctor)
 * Jo recalls ruining the Doctor's experiment on the day she first came into his laboratory. The Doctor admits that he did not realise how lucky he was to have her, for a time, but states that she was extraordinary from the very start. (TV: Terror of the Autons)
 * The Third Doctor manages to save Jo's life by exploiting the fact that he had over forty years to find a new solution, much like how the Tenth Doctor defeated the Weeping Angels in Blink.
 * Jo mentions the Doctor creating a time flow analog from corks and forks. (TV: The Time Monster)
 * Jo mentions her encounter with the Drashigs. (TV: Carnival of Monsters)