Confounding oaths

The year is 1815, and Mr. John Caesar is determined to orchestrate a successful coming-out for his younger sister, Mary. Despite his best efforts, he is thwarted by the various interventions of a ragtag regiment of soldiers, a mysterious military cult, and a malicious fairy godmother. When Mary is cursed by the fair folk, the dandyish Mr. Caesar is forced to work with the stolidly working-class.