 Romantic comedy which has Warren Beatty and Susannah York as a pair of amorous adventurers in the gambling places of London and the Riviera. Beatty is Barney Lincoln, a rambling gambling man who scores sensational wins at poker and chemin de fer because he has succeeded in marking the original plates for the backs of all the playing cards manufactured in a plant in Geneva and used in all the gambling joints in Europe. In his gambling depredation, Beatty is spotted by Angel McGinnis (York), the daughter of a Scotland Yard Inspector  Manny  McGinnis (Clive Revill) on the lookout for a man to do a job. The inspector enlists Barney s help in playing poker with a shady London character whom Scotland Yard wants to force to financial ruin.