STORY PLOTLINE

The TARDIS picks up a distress call and the Doctor and Sarah arrive on the planet Zeta Minor. There they discover that a Morestran geological expedition has fallen prey to an unseen killer and only the leader, Professor Sorenson, remains alive.

The DVD extras:

• Commentary - With actors Tom Baker, Elisabeth Sladen and Prentis Hancock, producer Philip Hinchcliffe
• A DARKER SIDE - Producer Philip Hinchcliffe, writer Louis Marks, designer Roger Murray-Leach, director David Maloney, actors Tom Baker, Elisabeth Sladen and Prentis Hancock
• PLANETARY PERFORMANCE - a look at the making of the story from an actor's perspective. With actors Tom Baker, Elisabeth Sladen, Prentis Hancock, Tony McEwan and Graham Weston
• STUDIO SCENE - the only surviving behind-the-scenes footage from the story
• Continuities - continuity announcements and repeat trailer
• Photo Gallery - production, design and publicity photos from the story
• Coming Soon trailer + Easter Egg