It's the most anticipated event of the decade -- Big Lou and Fat Bob's wedding -- and everyone is invited! But the relative peace and tranquillity of 44 Scotland Street is about to be disrupted. Domineering Irene is set to return for a two-month stay, consigning young Bertie to a summer camp. Not content with that, she somehow manages to come between the enigmatic nun, Sister Maria-Fiore dei Fiori di Montagna, and her friend, the hagiographer, Antonia Collie.