Barbados Quest plot
"There's Love and Treachery in RKO's Thrilling Mystery"
Wealthy American JD Everleigh buys a rare stamp in London from Geoffrey Blake, who says he represents stamp collector Robert Coburn. Everleigh suspects the stamp is a forgery and hires private detective Tom Martin to investigate. In London, Martin is assisted by Barney Wilson, a former criminal. Both find out that the real stamp is still in Lady Hawksley's possession. Lady Hawksley, however, refuses to show them this stamp. Martin befriends Jean Larson, Lady Hawksley's secretary, and learns that Blake is her employer's cousin. More and more, Martin has to determine that he is dealing with a gang of crooks, who also do not shy away from murder.