Seasons of Fear

In 2002, Seasons of Fear was released by Big Finish Productions.

Cover blurb
The TARDIS finally gets Charley to Singapore in time for the festivities. However, while she enjoys her young man's company, his Grandfather, Sebastian Grayle, taunts the Doctor. Apparently, they are old and bitter enemies and Grayle has finally succeeded in killing the Doctor.

With time running out, the Doctor and Charley must embark on a journey through history to discover how Grayle received the 'gift' of immortality and just how he has managed to destroy the Time Lord...

This story takes place after the TV movie.