Affirmative (short story)

 was a Brief Encounter short story published in Doctor Who Magazine 178.

Summary
K9 is busying himself in Leela's room on Gallifrey, recalling his adventures with the Fourth Doctor. Investigating an irregularity in his scan of the corridor, he meets the Seventh Doctor and recognizes him as his Master. Without alerting Leela to his presence, the Doctor takes K9's collar as a memento of his second best friend and silently leaves.

Characters

 * Seventh Doctor
 * Leela
 * K9

Continuity

 * K9 chose to stay behind with Leela when she remained on Gallifrey. (TV: The Invasion of Time)