Marine atomic tests cause changes in the ocean's ecosystem resulting in dangerous blobs of radiation and the resurrection of a dormant dinosaur which threatens London.
Gene Evans
Steve Karnes
André Morell
Prof. James Bickford
Leigh Madison
Jean Trevethan
John Turner
John
Alastair Hunter
Dr. C. A. Morris, the village doctor
Lloyd Lamble
Senior Admiral, at the Admiralty
Jack MacGowran
Dr. Sampson, the paleontologist
Maurice Kaufmann
Mini Submarine Officer
