A supermoon triggers a catastrophic transformation, turning billions into werewolves overnight. As the next supermoon approaches, scientist Dr. James Aranda (Lou Diamond Phillips) races to test a protective spray, Moonscreen. Meanwhile, ex-military Wesley (Frank Grillo) fortifies his sister-in-law's home against the impending chaos. When experiments go awry, both must confront the monstrous consequences of their actions while battling for survival against ravenous werewolves.