Larry Daley is a divorced father who can't seem to keep a job for more than a week. As a last resort, Larry applies for a job as a night shift security guard at the American Museum of Natural History. However, a seemingly easy job turns out to be an adventure when he finds that an ancient curse causes the "inhabitants" of the museum to come to life at night.

Boy and horse are shipwrecked on an island where they become fast friends. Upon their return home they work together for a try in one of the great races at Santa Anita.