When twin brothers Bill and Hal find their father's old monkey toy in the attic, a series of gruesome deaths start. The siblings decide to throw the toy away and move on with their lives, growing apart over the years.

In pursuit of a serial killer, an FBI agent uncovers a series of occult clues that she must solve to end his terrifying killing spree.

After undergoing an experiment that gives them monstrous side effects, Abbi, Tilda and Juan join forces to find the scientist responsible — and a cure.