When wistful introvert Alan Furnace meets quick-witted bombshell Beatrice, he has no idea of her secret life as "B. Monkey" -- the top thief-for-hire in London's criminal underworld. Charmed by Furnace's innocent and chivalrous ways, Beatrice resolves to reform. But to cash in on her first chance at real love, she must escape her former partner in crime, the ruthless Paul Neville -- and a dark past that seems to haunt her every step.