Growing up in post-World War II era Arizona, young Sammy Fabelman aspires to become a filmmaker as he reaches adolescence, but soon discovers a shattering family secret and explores how the power of films can help him see the truth.

On a weekend getaway at a rundown cabin in the woods, Jason, a cautious teen, his crude best friend Colin and his fearless older sister Summer are forced to work together, grow up and save their hard-partying parents from their predatory neighbor intent on feeding them all to her undead family.