The glamorous assassin Irma Eckman, disguised as an air stewardess, kills the oil tycoon Henry Keller with a booby-trapped cigar aboard his private jet, parachuting away before the plane explodes. She is picked up by a speedboat driven by her partner in crime, the equally beautiful Penelope. The villainous pair then murder David Wyngarde, making it look like a spear fishing accident. Sir John Bledlow, one of the directors of Phoenecian Oil, suspects that both deaths were the result of foul play; he had received an urgent message from Wyngarde that he needed to get in touch with Keller regarding a "matter of life and death". He asks Wyngarde's friend, Hugh "Bulldog" Drummond, to investigate.
