Eight-year-old Michael has lost his father. Michael's mother has thrown herself into work to avoid the grief. Determined not break a birthday tradition, Michael heads to the theme park accompanied only by his imaginary friend, a gorilla named Jam. Believing themselves to be space ninjas, they embark on exciting adventures. However, things go awry when they decide to save the park's elephant.

By the time Michael's mother realizes that her son is missing, Michael has been seriously injured by the violent elephant. However, the accident causes Michael and his mother learn to come to terms with Michael's father's death.