Into Mrs Dell's household at Dover comes the expected "distinguished personage", Mr Leroy, and his companion, Sophy. Mr Leroy purports to be the lost Dauphin - Louis 17th of France, but is in fact Sophy's Cockney uncle. Mrs Dell - her head full only of her forthcoming ball - allows Leroy to stay, hoping to announce his identity at the ball. The new music master, Mason, seems to have a hidden past; the mysterious Lady Atkyns would appear to know much about the Dauphin and Sophy changes allegiance as often as she changes beds. On the night of Waterloo no fewer than two further claimants to the French throne turn up at Mrs Dell's. But the true Dauphin - "he who was born gay" - has to take the only course open to him for Louis 18th, with an army of followers, is preparing to march on Paris.