| Episode cast overview, first billed only: |
 | Tim Pigott-Smith | - | Chief Constable John Stafford |
 | Karen Archer | - | Asst. Chief Constable Anne Stewart |
 | Judy Loe | - | Dr. Elizabeth Stafford |
| Jeremy Clyde | - | Sir Anthony Maylor |
 | Michael Cochrane | - | Nigel Crimmond |
 | T.P. McKenna | - | Colin Fowler |
 | Gary Waldhorn | - | Cllr. Alec Radcliffe |
| Eamon Boland | - | Det. Chief Supt. Jim Gray |
| Owen John O'Mahoney | - | Mark Jenkins (as Owen John O'Mahony) |
| Edward Clayton | - | Chief Supt. King |
| Tony Alleff | - | The Ship's Master (as Tony Allef) |
| Christopher Saul | - | Mr. Rogers |
| Olivier Pierre | - | Sergio Carese |
 | Christopher Muncke | - | Herr Neumann |
| Daniel André Pageon | - | Monsieur Huvelin (as Daniel Pageon) |
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