A physician is forced to operate on a mystery figure under shady circumstances.
| Actor | Role |
|---|---|
 Guy RolfeDr. Mark Fenton | Dr. Mark Fenton |
 Lisa DanielyLisa Durand | Lisa Durand |
 Patricia DaintonSister Rogers | Sister Rogers |
 Sydney TaflerWade | Wade |
 Ballard BerkeleyInspector Austin | Inspector Austin |
 Anton DiffringEdward Shroder | Edward Shroder |
 Brian WorthGeoffrey Terry | Geoffrey Terry |
 Avice LandoneMrs. Terry | Mrs. Terry |
| EEric BerryCol. Williams | Col. Williams |
 James RaglanSir Oliver Peters | Sir Oliver Peters |
| AAlexis ChesnakovShip's Captain | Ship's Captain |
 Michael GoldenHarrison | Harrison |
| EEdward DentithSergeant Lewis | Sergeant Lewis |
 Derek AylwardNot listed | Not listed |
 William FranklynDr. Gillespie | Dr. Gillespie |
 Desmond LlewelynPolice Constable at Barrier | Police Constable at Barrier |