Intrigued by a "personality quiz" that he found on the internet, teenage Calvin tricks his father Darren into taking him to a strange town not on any map which is home to a cult called "Sin Nombre" ("Without a Name"). Calvin is lured into the cult, which glorifies young people but is very dangerous to anyone 40 years or older. Local restaurateur Abigail -- whose own daughter April is already in the cult -- helps Darren to sneak inside Sin Nombre. Darren and Abigail try to convince Calvin and April to leave the cult but the kids may be in too deep.