A stirring tale of adventure, mystery, loyalty, and stolen treasure, Beau Geste is an excellent film on all levels, one of many enduring classics from 1939.
The film opens with an eerie scene of a company of Legionnaires approaching their fort at Zinderneuf and finding everyone dead - and the company's advance scout missing. (I guess the horror movie rule of never going to check things out alone wasn't common knowledge back then.) We then flash back to England, and the childhood of the three Geste brothers - John (Ray Milland), Digby (Robert Preston), and Michael (Gary Cooper), also called "Beau." (Beau geste is French for "noble/beautiful gesture.") They're the wards of Lady Brandon, who owns a fabulous sapphire called The Blue Water. When Lady Brandon's spendthrift husband plans to sell The Blue Water, it's stolen, supposedly by one of the three Geste brothers.