Intrigued by a "personality quiz" 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 murders those 40 or over. Abigail, whose own daughter is in the cult, helps Darren to sneak inside Sin Nombre. They meet Nine -- almost 40 and about to be murdered. Darren gets Calvin (renamed "Ten") out before the boy can order Darren's execution. Is Calvin in too deep already?