When Lord Michael Cynster learns of the mission his brother has been assisting with, he volunteers to help by hunting down a hoard of gunpowder now stashed somewhere in London. Michael's quest leads him to the Hendon Shipping Company, where his sole source of information is the fetchingly attractive Miss Cleome Hendon. Cleo offers him a bargain: she will lead him to the carters he seeks, but only if he agrees to include her as an equal partner in the mission.