"The waters surrounding an island become contaminated by chemical dumping, and people who eat fish caught in those waters become deformed and violent."
Ian Bannen
as Dr. Shaw
Judy Geeson
as Victoria Brown
John Paul
as Dr. Quist
George Sanders
as The Admiral
Simon Oates
as Dr. Ridge
Jean Trend
as Dr. Fay Chantry
Joby Blanshard
as Bradley
Percy Herbert
as Hartwell
Shelagh Fraser
as Mrs. Betty Straker
Geoffrey Keen
as Sir Henry Leyton
Joseph O'Conor
as Vicar
Norman Bird
as Brewer
Constance Chapman
as Miss Johnson
Michael Brennan
as Tom Straker
James Cosmo
as Bob Gillette
Cyril Cross
as George
George Woodbridge
as Ferry Skipper
Jerome Willis
as Lt. Com. Tavener
Jeremy Child
as David Broome
Brian Anthony
as Brian Murray
Rita Davies
as Mrs. Murray
Walter Turner
as Mr. Murray
Paddy Ryan
as Grandfather Murray
Reg Lever
as Sam
Pam St. Clement
as Young Woman
Michael Hopkins
Sound Editor
Peter Sasdy
Director
Clive Exton
Screenplay
Kenneth Talbot
Director of Photography
Ken Softley
Construction Manager
Doreen Soan
Continuity
Kit Pedler
Series Writer
Eddy Joseph
Assistant Editor
Ronnie Maasz
Camera Operator
Ron Barron
Sound Recordist
Gerry Davis
Tony Tenser
Producer
Tom Smith
Makeup Supervisor
Alan Cassie
Draughtsman
Jim Brennan
Location Manager
Jack Causey
Production Manager
Ronald Anscombe
Focus Puller
Colin Grimes
Art Direction
Anne McFadyen
Hair Supervisor
Derek Whitehurst
Assistant Director
Sue Gentle
Stand In
John Scott
Original Music Composer
John Hilling
Wardrobe Master
Keith Palmer
Editor