An American insurance investigator is sent to Rhodesia to investigate the mysterious death of a diamond broker who drowned whilst diving off the coast. The broker was insured for $1 million so the insurers are suspicious.

Dana Andrews
as Scott Walters

Jeanne Crain
as Marian Taylor

David Farrar
as Perry Henderson / Arthur Henderson

Patrick Barr
as Supt. Roberts

George Coulouris
as Capt. Malburn

Charles Goldner
as Martell

Wilfrid Hyde-White
as Pitt

Heather Thatcher
as Lady on the Niagara

Michael Mataka
as Vincent

Paul Carpenter
as Pan American Airways Clerk