After a year up the Amazon "without seeing a white woman", ale heir and keen ophiologist (look it up) Charles Pike (Henry Fonda) is targeted by con woman Jean Harrington (Barbara Stanwyck) and her card-sharp father (Charles Coburn) as prime sucker material. Jean actually falls for the naive mug, but when he finds out she's a crook the shipboard romance fizzles. To get revenge, Jean reinvents herself as an English debutante, "Lady Eve Sidwich", and shows up at the Pike estate intent on breaking a heart. You can probably guess the end, but not the path which is taken to get there - the left-field kinks are all part of the fun.
Writer-director Preston Sturges was a rare Hollywood man whose comedy hits were popular successes but also prized and praised by high-toned critics (and, not least, peers like Orson Welles and Billy Wilder). He was as at home sending up the snobbish absurdities of the wealthy-but-vulgar Pikes as he was with the cheerfully crafty world of down-to-earth slobs. Not everything in The Lady Eve is as frothy as it might be - Fonda's repeated pratfalls become uncomfortable rather than funny, but never go as far into the comedy of agony as Cary Grant in his screwball roles - but it's still a wonderful picture, set (despite a good Hitler joke) in a world of silly heirs and sharp-eyed dolls as remote from reality and yet wholly credible as that of P. G. Wodehouse.
The bit about being away from "white women" sounds like conventional 1940s racism, but is actually a sly joke on Fonda's blinkered asexuality - the jungle is draped with native lovelies he's ignored but who have made an impression on his bodyguard (William Demarest). Among the funniest moments is Stanwyckís commentary on the parade of flirts and gold-diggers trying to get the rich boob's attention, but her performance makes this more than just the funny tale of a woman pursuing an idiot. Her Jean/Eve is every bit as devastating, in midriff-bare evening gowns, as her murderess in Double Indemnity, and still charms and fascinates.