X: The Unknown

Army radiation experiments awaken a subterranean monster from a fissure that feeds on energy and proceeds to terrorise a remote Scottish village. An American research scientist at a nearby nuclear plant joins with a British investigator to discover why the victims were radioactively burned and why, shortly thereafter, a series of radiation-related incidents are occurring in an ever-growing straight line away from the fissure.

• 
  Leslie Norman
• 
  Christopher Sutton
• 
  June Randall

• 
  Dean Jagger
  Dr. Adam Royston
• 
  Leo McKern
  Inspector McGill
• 
  William Lucas
  Peter Elliott
• 
  Edward Chapman
  John Elliott
• 
  John Harvey
  Maj. Cartwright
• 
  Michael Ripper
  Sgt. Harry Grimsdyke
• 
  Anthony Newley
  LCpl. 'Spider' Webb
• 
  Ian MacNaughton
  Pvt. Haggis
• 
  Peter Hammond
  Lt. Bannerman
• 
  Kenneth Cope
  Pvt. Lansing
• 
  Michael Brooke
  Willie Harding
• 
  Frazer Hines
  Ian Osborn
• 
  Neil Wilson
  Russell
• 
  Stella Kimball
  Willie's Nurse
• 
  Jameson Clark
  Jack Harding
• 
  Jane Aird
  Vi Harding
• 
  Neil Hallett
  Harry, the amorous intern
• 
  Marianne Brauns
  Zena, the amorous nurse
• 
  Max Brimmell
  Hospital Superintendant
• 
  Brown Derby
  The Vicar