This six episode serial hails from the very first TV series in 1964 and stars William Hartnell as the Doctor with William Russell, Jacqueline Hill, and Carole Anne Ford as his companions. Written by Peter R. Newman.

The TARDIS travellers discover that the crew of an Earth spaceship have been hijacked by the Sensorites, and they in turn are transported to the aliens' planet. Humans and Sensorites alike are stricken by a deadly illness, for which the Doctor struggles to find a cure.

The remastered soundtrack of this classic BBC-TV adventure is accompanied by linking narration from a member of the original cast. A bonus interview is also included.