When Jo Smith arrives for an audition with director Vyvian Jones, it turns out she’s actually been invited to the theatre by Vyvian's twin brother Beverley, who wants her to impersonate her own twin sister Fiona, to persuade Vyvian that Beverley hasn’t had a fling with Fiona... he has, but doesn't want Vyvian to tell his fiancee Cheryl!

And when the real Fiona turns up, not to mention Vyvian (a member of the local Sons of Satan Association, who wants to use Jo for his first human sacrifice) and Beverley and Vyvian’s identical triplet policeman brother, the stage is well and truly set for a fast-moving madcap comedy of multiple mistaken identity.