A review by wealhtheow
Doctor Who and the Keeper of Traken by Terrance Dicks

3.0

On the peaceful world of Traken, even evil cannot survive long. The last dark power on the planet, Melkur, is slowly dying--but not slowly enough. It takes all the resources of the Doctor, Adric, and the aged Keeper of Traken to beat back Melkur's ambition.