Benjamin Pratt and his friend Jan try to prevent bulldozers from knocking down their school, but the evil janitor--who is not actually a janitor--is hot on their trail.

"The Keepers of the School--known to their friends as Ben, Jill, and Robert--have one last chance to save their school before it's torn down to make room for a seaside amusement park. But their nemeses, janitors Lyman and Wally, are just as determined to keep the kids out of the way and the demolition on schedule"--Provided by publisher.

As the new Keepers of the School, sixth-graders Ben and Jill must decipher a handful of clues written as maritime riddles to save their school from demolition by a greedy company.