Without his father, Arlo shoulders more of the workload. He spots the same caveboy inside the silo and, blaming him for his father's death, chases him until both fall into a river. Arlo cannot swim, and is swept downstream where he hits his head on a rock and is knocked unconscious. Awakening, he finds himself far from home and tries to survive on his own, but becomes trapped when a boulder pins his leg. The next day Arlo wakes to find his leg has been freed, and the caveboy appears with food for him. The caveboy then leads Arlo to a berry tree, where the caveboy fends off a large snake, amazing Arlo and impressing a nearby eccentric Styracosaurus who wants to keep the boy. He forces Arlo to compete with him to give the boy a name he will respond to, which Arlo finally wins when he calls him "Spot". Arlo and Spot bond as Arlo laments his lost family, and Spot reveals that his own parents are dead. Later, when a storm strikes, Arlo runs away in fear and loses the riverbank he has been following home.