Julian, Dick, Anne and George are on a train, approaching Kirrin, where they are to spend the Easter holidays. However, there is no-one to meet them, not even Tim. Convinced something is wrong, George rushes poste-haste to Kirrin Cottage, in a taxi.

When the other three reach the cottage, they find George in tears. How like a girl! Surprise, surprise; illness has just struck Kirrin Cottage again. Poor old Joan has scarlet fever, has to go to hospital and Quentin and Fanny are in quarantine inside, and cannot let the children in. What are they to do?