At the roulette table an elderly, ludicrously made-up woman in dazzling diamonds is making a killing. Who would guess the bejewelled high roller is actually retired art teacher Miss Emily Seeton, in disguise to help capture a mysterious crime boss? Miss S. must get a good look at the crook's face to produce a sketch for the police, a simple task surely. It's not her fault things escalate, and after half-blinding one baddie with the tail of her mink stole and whacking another with her handbag, she's soon gambling for the very highest stakes - her own life. Serene amidst every kind of skullduggery, this eccentric English spinster steps in where Scotland Yard stumbles, armed with nothing more than her sketchpad and umbrella!