The Doctor and his companions land on a spaceship orbiting a distant and mysterious world, where a human crew lie 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?

Special Features:

• Commentary
• Looking for Peter - Toby Hadoke goes in search of the enigmatic Peter R Newman.
• Vision On - What exactly does a Vision Mixer do?
• Secret Voices of the Sense-Sphere - Clive Doig reveals the origins of the eerie Sensorite voices.
• Photo Gallery
• Coming Soon Trailer
• Radio Times Listings
• Production Subtitles
• Programme Subtitles
• Digitally Remastered Picture and Sound Quality