Jesse McCall is having trouble making friends at his new school, but in spite of that, Jesse isn’t lonely—he’s too busy going on adventures with his imaginary pirate, the Terrible One-Eyed Jack. Jesse and One-Eyed Jack are determined to find buried treasure, but they run into trouble along the way when an outlaw pirate, Red Legs Ricky, steals their treasure map! A high-seas adventure ensues, and Jesse soon discovers that friendship is the greatest treasure of all.