The film is set in a suburban fantasy world populated by elves, trolls, and spirits, where unicorns roam through trash cans like candy-striped possums. The film offers a premise that magic is real, but it has long been forgotten and replaced by modern technology. A pair of teenage brothers, whose father died when they were still young, decide to enter this fantasy world to spend one last magical day with their father. Holland voices the younger brother Ian, Pratt voices the noisy older brother, Dreyfuss voices the brothers' mother, and Spencer will use his voice to his advantage.