The Return of the Living Dead series reaches its nadir in this fourth installment, which limped onto DVD and cable schedules two decades after the original film. The self-referential humor, cartoon thrills, and cheaply inventive special effects of the earlier movies have completely vanished, replaced by turgid teen melodrama and poorly paced action. Though it's sad to see Peter Coyote reduced to this sort of thing, the interchangeable young leads prove inoffensive enough. Really, it's the cut-rate script by William Butler and Aaron Strongoni and the plodding direction of Ellory Elkayem that deserve scorn. Every quickie horror flick provides its makers with the chance to prove that a smart screenplay and a lot of fake blood can trump a big budget. Sadly, this rote exercise wastes any such opportunity.