Born to a father set on having adventures, Prudence and Robin Tremaine have lived a life on the run. They constantly are moving (often fleeing) from one place to another, and often have to do so in disguise. After Robin and his father take part in the failed Jacobite rebellion they split up and flee into the country side. Robin meets up with his sister, who stayed out of it, and they decide to swap genders to thoroughly hide Robin in the last place anyone will ever look – in a set of petticoats – to prevent him from being hanged. Prudence then becomes Mr Peter Marriot and Robin becomes Miss Kate Marriot.
Together they travel to London and hope to meet up with their father there. That’s when they meet Sir Anthony and Letitia, Letty is currently attempting to elope with a Mr Markham only to find that he is a brute and not worth marrying, her attempt to change his mind on this score proves dangerous though. With the siblings help (a false swoon by “Kate” and a swift uppercut with the hilt of a sword by “Peter”) they rescue Letty and restore her to Sir Anthony, a friend of her father’s. In that meeting “Kate”, er, Robin falls hopelessly in love with Letty and “Peter”, er, Prudence falls hopelessly in love with Sir Anthony. Now, in true Georgette Heyer fashion, the stage is set for a romp unlike any other!