Alec Firth is having an affair with his assistant, Liz, and has organized his domestic life so that they can go to Spain on holiday without making Alec's wife Maggie remotely suspicious, what could possibly go wrong?

Plenty. On the doorstep, in dizzyingly rapid succession, are: Phoebe, Alec's mother, who has discharged herself from her old people's home; Alec's son Jamie, with a broken ankle; and his daughter, heavily pregnant and not planning to marry the child's father ...