Sixth-grader Ben Pratt's life is full of changes that he does not like--his parents' separation and the plan to demolish his seaside school to build an amusement park--but when the school janitor gives him a tarnished coin with some old engravings and then dies, Ben is drawn into an effort to keep the school from being destroyed.

As Benjamin Pratt and his friends Jill and Robert continue their efforts to save their school, they find themselves dodging two evil janitors, Lyman and Wally, but their team has also grown and now has a secret fund of millions of dollars.