Michael Richards may be a recent arrival to this town and fifth grade but he already knows three things: his new friend Wart is crazy, he needs to come up with the best Halloween costume of his life, and something strange is going on at the old mansion on the hill. Mysterious happenings have suspicious fingers pointing at the odd man who lives there. Gabriella Sanchez, Michael's next-door neighbor and classmate, believes the man is innocent. She is the only one that does. Halloween plans get put on hold to investigate. Wart's inquisitive meddling leads Michael to information he wished he didn't have. People have gone missing. Ten thousand dollars cannot be accounted for. The three friends believe answers are hidden in the mansion cellar, where they discover a little curiosity can be a very dangerous thing.