Mrs and Mrs Cooper are staying at a boarding-house in the seaside resort of Morecambe with their small children, Colin and Jennifer. Mr Cooper has just been made redundant, but the family are trying to keep this a secret from the other guests. Also staying at the hotel are Keith and Jo, a young couple on their honeymoon, and an older couple, Mr and Mrs Thornton. Waking early one morning, Colin amuses himself by dangling one of his sister's sandals out of the window on a piece of string. The sandal accidentally lands on a flat roof just outside the window of the honeymooning couple, and his father's now straitened financial circumstances mean Colin has to get it back, by fair means or foul.