Sisters of the Flame

In 2008, Sisters of the Flame was released by Big Finish Productions.

Cover blurb
The richest man in the galaxy has just bought a backwards planet with no obvious mineral wealth in the outer reaches of the universe. An obscure mystical sect has been revived after centuries of neglect. A new race of aliens are hunting for prey. Why?

As the Doctor and Lucie attempt to discover the answer, it becomes clear that someone is attempting to resurrect the past - and they need a Time Lord to help them achieve it.