Regeneration Impossible (audio story)

 was the fifth story of the tenth season of Big Finish Productions' Short Trips series.

Publisher's summary
The Doctor is in his TARDIS atop a cloud above Victorian London. He’s retired, no longer interfering in the affairs of others. There’s nothing that could make him help anyone else. Except, perhaps, the lure of another Time Lord...

The Doctor is locked in a mortuary in Victorian London, dying. He can’t escape and doesn’t know how to keep himself alive. Just when he thinks it can’t get any worse, he finds himself locked in with the one person he hates most in the entire universe.

Himself.

Plot
to be added

Characters

 * Eleventh Doctor
 * Twelfth Doctor
 * Gregory Chapman

Continuity

 * The Eleventh Doctor mistakes the Twelfth Doctor for the Master. (TV: Terror of the Autons, etc)
 * The Eleventh Doctor learns that he is to save Gallifrey. (TV: The Day of the Doctor)
 * The Twelfth Doctor refers to himself as "the man who stops the monsters." (TV: Flatline)
 * The Twelfth Doctor refers to his past association with UNIT. (TV: The Invasion, etc)
 * Gregory Chapman uses a Time Ring. (TV: Genesis of the Daleks, Revenge of the Cybermen)
 * The Eleventh Doctor believes he is the last incarnation of his regeneration cycle. (TV: The Time of the Doctor, PROSE: Four Doctors)