Doctor Who and the Planet of Evil — Terrance Dicks

A survey team of eight men from the mighty Morestran Empire landds on Zeta Minor, a remote planet on the fringes of the universe. Before their expedition is over, seven of the men are mysteriously and horrifically murdered.

A distress signal brings the Doctor to the planet--but his good intentions are not appreciated. The commander of a Morestran rescue party, sent to investigate the disappearance of the survey team, is convinced the Doctor is the killer.

And while the Doctor is kept prisoner and powerless to act, the merciless hell-planet claims even more victims...