Numbuh 1 and his father are aboard a plane, going back to their old homeland of England--Numbuh 1 complains to his dad that he has no real memory of actually living in England, since they and Numbuh 1's mom moved to the United States when Numbuh 1 was only three years old. Monty feels this trip will be a good experience for him. A boy next to him, named Trevor, reveals himself as being on a mission to return a book to where it belongs. Numbuh 1 wants to know more about it but Trevor says not until they're out of the plane.