The story follows the Famous Five — Julian, Dick, Anne, George (Georgina), and Timmy the dog — as they spend their Christmas holidays at George's home, Kirrin Cottage.
A tutor named Mr. Roland is hired to help the children with their studies, but the Five become suspicious of him. They soon discover a hidden map in the old house that points to secret passages.
When valuable scientific papers from George’s father are stolen, the children suspect that Mr. Roland and two art dealers are behind it. Using their courage and teamwork, the Five explore the secret passages, recover the stolen documents, and expose the criminals.
