Simon Templar competes in a speedboat race and witnesses one of his fellow competitors, Oscar West, in trouble. West's speedboat subsequently explodes. The coroner rules that it has been an accidental death, although no bodies were recovered. West's widow, Annabel, discovers from her lawyer that despite her husband's extravagant lifestyle, he was actually broke. The only remaining asset is a boat registered to her, 'The Brave Goose'. Annabel travels to the French Riviera to sell the boat, but is kidnapped by three hoodlums who, it transpires, are colleagues of her late husband. The four men had been involved in a gold heist, but West had hoodwinked his partners, who wound up serving time. They believe that Annabel holds the key to where the gold is hidden. Templar comes to Annabel's rescue as the dashing buccaneer but soon she has doubts about his intentions when she discovers the gang had one more accomplice, whose identity was known to Oscar alone ...