Houdi, a seventh-grader in Mr. Kelly's class, discovers something valuable hidden beneath the stairs of the newly restored Elk Grove House and Stage Stop Museum. Little does he know that his new found treasure is a historical artifact that will awaken the ghosts of the past who would do anything to get it back.

Fasten your seat belts and ride along on this fun, fast-paced roller coaster adventure, as Houdi and his friends uncover the secrets that lead to another amazing discovery!