Lights. Camera. Slawter! Grubbs Grady and his half-brother Bill-E are thrilled to join their uncle Dervish as onset consultants for the newest movie by cult horror producer David A Haym. Shot in a deserted town renamed Slawter, the demon-themed movie is to be Haym's masterpiece. But as strange incidents disrupt the set, Grubbs begins to wonder whether more than filming is afoot.