Mandrake, having solved a seemingly related murder case in New York, joins his companions Narda, Lothar, and Karma on a yacht for a secret mission arranged by Inter Intel. The mission, revealed by Captain Hooker, involves landing a squad of Marines on Klipper Island, owned by the criminal Benbova, to locate a missing US submarine and rescue its crew. Mandrake's role is to provide cover for the operation using his magician persona and stage illusions, while also ensuring the marines' safe return. The yacht, named "Phandrake," is sailing through the Pacific after passing through the Panama Canal.
