A review by barefootsong
The Roots of Evil by Philip Reeve

3.0

An interesting adventure in which the Fourth Doctor and Leela visit a wooden space station made up of a sentient tree(!) and inhabited by a colony of humans that have been waiting a long time for the Doctor to return....

Leela's observation of the Doctor at one point: "Sometimes he was like a child, sometimes a god. Often he seemed to be both at once." Spot on.