Caught in the Act

William's efforts to mend a leaking tap only make things worse, requiring a visit from the plumber. Even worse, Peter's parents, Margaret and Henry Richardson, arrive unannounced and want to stay overnight. The Fields invent a planned visit to Bournemouth and hide at Sonia's, but then the Richardsons call on Sonia and the Fields flee to Nancy's flat - where they're mistaken for burglars. They explain that they had to return early when Nancy caught the flu, but then Henry actually catches it, so the Fields are stuck with the Richardsons for a few days.