Rosie is thrilled when the family remember her birthday and present her with flowers and chocolates. Preparations begin in earnest for the barbecue and everyone is invited. Meanwhile, Pauline is annoyed when she discovers that the flowers at Arthur's bench have mysteriously disappeared.

Most of the Square turn out for the party and Keith is particularly proud of his famous barbecue sauce, concocted specially for the event. However, the sauce proves to have more of an impact than he expected.