Doctor Who: Galaxy 4

With the planet about to explode, the Doctor and his companions are racing against time to save themselves and the Rills. But Maaga and the Drahvins have plans to steal the only working ship on the planet and being the only ones on it.

While trapped in the Rill spaceship, Vicki discovers that the Rills aren't what the Drahvins said they were. Meanwhile, Steven is trapped in the air lock after failing to escape Maaga's grip, and the oxygen is running out.

With Maaga holding Steven as hostage, the Doctor and Victoria have no choice but to investigate the Rill's spaceship. There, they discover the operation behind the Chumbelys, and come face-to-face with the mysterious Rills.

Arriving on an arid planet, the Doctor and his companions encounter the Drahvins, a species stranded on the planet, which is soon doomed to explode. But the only functioning ship is in the hands of another mysterious species, the Rills.

A Teaser Trailer for the animated version of the story.

Toby Hadoke visits actors Peter Purves to discuss the serial with contributions from actors Maureen O'Brien, and Lyn Ashley, vision mixer Clive Doig, special sound designer Brian Hodgson and Mike Pinefield, son of the serial's original director Mervin Pinfield. Other contributions include writer William Emms, designer Richard Hunt, and Derek Martinus.

Images from the BBC Photo Library, Jan Vincent-Rudski and Jessica Carney, accompanied by sound effects for the serial by Brian Hodgson.

Presented here with a commentary moderated by Toby Hadoke and featuring Maureen O'Brien, Peter Purves and Lyn Ashley.