Ben Pratt was worried about Ms. Wilson, his homeroom teacher, busting him for being late. At least, that's what he was worried about until he found Mr. Keane, the janitor, in distress. Before the ambulance arrived to take Mr. Keane to the ambulance, the janitor forced Ben to take a coin that had been protected by a long line of janitors at Oakes School. The back of the coin had this message: "First & always my school belongs to the children. Defend it. 1783." Mr. Keane also warned Ben that he had told Lyman, the new assistant janitor too much.

Oakes School was purchased by a company planning to turn the area into an amusement park. Unsure what to do about the coin, Ben asked his friend Jill for information about Duncan Oakes, the captain who started the school and who had a strange grave built for himself in the middle of what is now the school playground. Mr. Keane's sudden death made Ben all the more determined to figure out what was going on. Trying to keep ahead of the ever suspicious Lyman while searching for clues around the school with Jill became harder other distractions, such as his parents' separation and a boat race against bully Robert, get in the way.

This was a fun adventure story to read. Not much is resolved at the end of the book, which does make this a good stand-alone read. I'm curious to see what happens in the second book.