As long as he remembers to stay smart and keep his eyes open, Mateo knows that he can survive the trek across the Sonoran Desert that will take him from Mexico to the United States. But the Sonoran Desert, with its hostile temperatures and inhabitants, is teeming with danger as the Border Patrol and rogue militias prowl its deadly terrain. With the odds stacked against him, his one chance at survival may be putting his trust in Guillermo, a ghost who has spent his afterlife guiding migrants to safety.