Kind-hearted Miss Hannah Pym is off to Portsmouth in the company of the beautiful but practical Miss Penelope Wilkins. Miss Pym quickly realises that Penelope needs someone to enliven her sheltered life, someone perhaps like their handsome travelling companion, Lord Augustus Railton. Penelope, however, thinks Lord Augustus is a ne'er-do-well...

Hannah's hopes for adventure, on the other hand, are fulfilled when the coach happens upon a footman who faces hanging for a crime he didn't commit.