Ben attends the Captain Oakes School in Edgeport, Massachusetts. The school was established in the 18th century by a sea captain, Duncan Oakes, and has remained ever since. But it is now in danger of being torn down and replaced by a water amusement park.
Before cranky old janitor Keane is rushed away in an ambulance, he catches Ben and gives him a coin which reads "First and always my school belongs to the children, DEFEND IT, Duncan Oakes, 1783." He tells Ben not to trust any of the adults at the school, including the new assistant janitor.
So it's up to Ben and his friend, Jill, to save the school. The question is: How? They have to follow a series of clues to figure it out. On top of that, he is also dealing with the separation of his parents and preparing for his upcoming sailboat race against his biggest rival, Robert. Will Ben and Jill be able to follow the clues and escape detection of this new, suspicious janitor? Will Ben beat Robert in the boat race? You know how to find out.