Twelve-year-old Greta's dad wakes her up before dawn and crams her and her siblings into a station wagon. They set off on a journey from New England to California. On the way, Tom assures the kids that Mom will soon join them. Greta believes him at first, older sister Caroline nonchalantly accepts his stories, and nine-year-old Nat is too young to suspect a thing. But Tom's mood shifts often, and the kids soon find themselves in unpleasant and dangerous situations.