Frontios

The TARDIS materialises in the far future, a period in time even the Doctor is unhappy about visiting as it is crucial it is left alone. The Doctor, Tegan and Turlough find a struggling colony, lead by Plantagenet, is under attack from meteorite attacks.

At the same time colonists are disappearing, literally sucked into the earth. The Doctor unwittingly helps the colonists, and ventures underground. Turlough recognises the creatures responsible, and also goes insane when he realises that the Tractators are involved.

The Tractators have been burrowing underground, creating a network of almost perfectly smooth corridors, with the aim of turning Frontios into a form of space vehicle. Turlough recalls that the way to render Tractators harmless is to separate them from the Gravis.

The Tractators have managed to get into, and break up, the TARDIS. The Doctor tricks the Gravis into reassembling and freeing the TARDIS and takes the Gravis to an uninhabited planet, rendering the Tractators harmless.

• Chief Orderly Brazen: Peter Gilmore;
• Norna: Lesley Dunlop;
• Chief Science Officer Range: William Lucas;
• Plantagenet: Jeff Rawle;
• Cockerhill: Maurice O'Connell;
• Orderly: Richard Ashley (1);
• The Gravis: John Gillet (2-4);
• Tractators: (all 2-4) William Bowen, George Campbell, Heidi Khursandi, Michael Malcolm, Stephen Speed;
• Retrograde: Raymond Murtagh (3-4);
• Deputy: Alison Skilbeck (3);


• UNCREDITED CAST:
• Paramedic: Judy Collins (1);
• Warnsmen: Jim Dowdall (1);
• Retrogrades: Terence Brook, Peter Creasey. Steve Emerson, Anthony Freeman, James Lyon, Mike Molloy;
• Captain Revere: John Beardsmore (1,3-4);
• Excavator Machine Operators: (all 3-4) Paul Andrew, Salo Gardner, Llewellyn Williams;
• Orderlies: Richard Ashley, Rodney Cardiff, Daniel D'Arcey, John Greening, Chris Holmes, Paul Lowther, Ian Marshall, Barry McKenna, Keith Norrish, Miles Ross, John Hamilton Russell, Richard Smythe;
• Paramedics: Kevin Goss, Linda Kent, Dominic Reyntiens;
• Patients: Rita Daniels, Barbie Denham, Alan Forbes, Michael Jeffries, Jay McGrath, Joe Phillips, Sue Somerset;
• Colonists: Terry Bradford, Peter Gates Fleming, Laurie Goode, Robert Goodman, Caroline Haigh, Judith Jeffrey, Fernanda Monast, Robert Peters, Monica Ramone, Penny Rigden;