The Champions go to sea on a macabre trip to reconstruct the voyage of a nuclear submarine which has been found with its entire crew dead.
The U.S. nuclear submarine Kepple, which has been on a round-the-world voyage, is found drifting off the Irish coast with her entire crew dead. The cause of death is a mystery.
What strange tragedy has hit the vessel? The three Nemesis agents Craig (STUART DAMON), Sharron (ALEXANDRA BASTEDO) and Richard (WILLIAM GAUNT) are selected to go aboard when the Navy decides to reconstruct the Kepples voyage.
They are able to estimate the approximate area where the deaths probably took place, but there is plenty of drama before they reach this area, part of which is caused by the discovery of a newspaper reporter, Stantin (JAMES MAXWELL), who has smuggled himself aboard in the guise of a sailor.
Damaged through striking an uncharted underwater-reef, and, with the radio out of order, the submarine surfaces close to a strange island. Craig and Richard go ashore with two seamen. The island is apparently devoid of life, but there is a thin green mist in the air. The two seamen drop dead; Craig and Richard slump unconscious to the ground and then find themselves prisoners of a dedicated but ruthless scientist named Minoes (MARNE MAITLAND) who, working underground, is experimenting with a new type of poison gas which leaves no trace.
It now becomes clear that the Kepples crew became victims of the gas when the submarine came across the island; but Craig and Richard are beginning to wonder if they will ever be able to make their report. Minoes, worried because they have been able to survive, prepares to pump more gas into the sealed chambers in which they are captive. Richard is to be gassed first, but he manages to break out of his cell via an air conditioning shaft. When Minoes enters, he himself is gassed as he and the reporter Stanton, who has followed the Champions to the island, fight for possession of the one gas mask available.
Craig, too, has succeeded in escaping. But as he and Richard are about to leave, they find themselves in a bitter fight with Stanton. The outcome is that even the super-human qualities of the Champions are in danger of being unable to resist the lethal gas...
Series created by
Monty Berman and Dennis Spooner
© Copyright Incorporated Television Co. Ltd. MCMLXVII
David Blake Kelly
| Lighthouse Keepers
Director of photography
Theme composed by
Associate art director
Second unit director
Second unit cameraman
A.J. Van Montagu
Made on location and at
ASSOCIATED BRITISH ELSTREE STUDIOS