Doctor Who: The Sensorites

The Doctor, Ian, Barbara and Susan land on a spaceship orbiting a distant and mysterious world, where a human crew lies frozen somewhere between life and death. The planet is the Sense-Sphere, home of the Sensorites, beings of immense intelligence and power. Unable to leave, the Doctor and his companions must deduce the Sensorites' intentions: are they friendly, hostile, or frightened? And what is the deadly secret at the heart of the Sense-Sphere?