The Christmas Inversion (short story)

 was the third short story in Twelve Doctors of Christmas, featuring the Third Doctor.

Summary
Answering a distress call from 21st century London, the Doctor, Jo Grant and Captain Yates encounter a remarkable woman named Jackie Tyler, convinced that the Doctor has changed "again" and that Jo is her daughter Rose! As they survive malicious holiday decorations, attempt to assist the contemporary UNIT personnel and discover the Master's latest scheme gone awry, Jo wonders if her absence from the future Doctor's life is a ghost of her Christmas future...

Characters

 * Third Doctor
 * Jo Grant
 * Captain Mike Yates
 * Tenth Doctor
 * Jackie Tyler
 * Harriet Jones

Worldbuilding

 * The Third Doctor is unfamiliar with the Slitheen.

Continuity

 * Jackie mentions the Slitheen, the pig crashing into Big Ben, and Harriet Jones helping save the world. (TV: Aliens of London, World War Three)
 * The Doctor mentions the "Omega business". (TV: The Three Doctors)
 * Jackie believes that the Doctor has regenerated again, and, when meeting Jo and Yates, she thinks that Rose and Mickey have also changed their appearance. (TV: The Christmas Invasion)
 * UNIT's secret HQ is no longer located inside a building marked with a sign which reads "UNIT Headquarters," (TV: The Five Doctors) and is instead in a base under the Tower of London. (TV: The Power of Three)
 * Jackie recalls that Rose went back to "certain death" to save the Ninth Doctor. (TV: The Parting of the Ways)
 * After hearing Jackie talk about Britain's Golden Age, Mike Yates remarks that a golden age "sounds good". (TV: Invasion of the Dinosaurs)
 * Jackie recalls Rose telling her that she had met her father before his death. (TV: Father's Day, The Parting of the Ways)
 * When Mike Yates mentions UNIT's name as "United Nations Intelligence Taskforce", the Tower guard notes that its now "Unified Intelligence [Taskforce]." This same discrepancy was noted in a conversation between Jack Harkness and John Benton. (COMIC: Official Secrets)
 * The name central control console was previously used in PROSE: Memorandum.