STORYLINE
The TARDIS crew arrive on a seemingly deserted spaceship, only to find what appears to be the dead bodies of the ship's original crew. But the crewmembers are far from dead - instead they are under some form of mental attack that keeps them prisoners in space...
The ship is trapped in orbit around the Sense-Sphere, home world of the alien Sensorites. The Doctor, Ian, Barbara and Susan are warned to leave, but before they can do so, the TARDIS is attacked, and its lock is stolen.
The Sensorites are using their telepathic powers against the human visitors to their world. And the TARDIS crew now find themselves helpless captives of the the Sensorites, and their mental powers...