A van full of illegal Mexican immigrants is discovered on the side of the road, brutally murdered by some supernatural force. Trying to find answers, Sam and Dean are plunged into a dangerous reality along the Mexican border. They meet a tattooed, pistol-wielding girl on a motorcycle who seems to be getting everywhere before them. Shochi Kasadora opens a completely new world of monsters to the Winchesters. The events of the book take place within the sixth season, between the episodes “Locked Up” and “You Can’t Escape Fate.”