Aside from Felix Aylmer's appearance as the President of his South American country, I hadn't really heard of many of the cast of jobbing British actors drafted in for this amiable crime caper. High-roller "Mortimer" (Donald Stewart) is determined to close a big deal but is neglecting his increasingly bored wife "Teri" (Anne Crawford). Intent on getting his attention, she goes to an high-end jewellers where she has discovered the eponymous diamond is being sold. Now one of her husband's underlings has alerted his boss to her visit and once they are both there, things start to hot up! A robbery... read the rest.