Julian, Dick, Anne and George are together again for the Christmas holidays. Because of illness at home they stay at Kirrin Cottage with George's parents. Uncle Quentin is working on a secret theory and a tutor is hired for the children. The story follows their return to Kirrin and the beginning of their holiday adventures.
This is the second book in Enid Blyton's Famous Five series. It follows Julian, Dick, Anne and George as they return to Kirrin Cottage for the Christmas holidays. The story is aimed at children who enjoy adventure and mystery stories.
The book opens at Gaylands School where Anne receives a letter from her father. Her mother has scarlet fever so the children cannot go home for Christmas. Instead they are invited to stay with George at Kirrin Cottage. A tutor is arranged for the holidays because Julian and Dick have fallen behind with their schoolwork after illness.
The children travel to Kirrin. George's mother Aunt Fanny meets them at the station. Uncle Quentin is working hard on a secret theory which he plans to present to a high authority. The children learn that the sea is too rough in winter to visit Kirrin Island. Timothy the dog has caused trouble at school by chewing slippers and eating a steak pie.
The boys arrive the next day. The children are reunited at the station with much excitement. The stage is set for the holiday adventures that follow at Kirrin Cottage.