After he is attacked by a teenager with a grisly condition that turns her into a psychopath when she sleeps, a detective pursues her across the country even as he succumbs to the same disorder.
What's the old saying, "Don't kick a sleeping dog"?
Even if it's your own pet, when it wakes up it might bite you!
Thus, an intended cure for a young, comatose patient goes horribly wrong, and the initial victims are not just the innocent teenager, but a cop who is first to arrive on the scene.
Because as he responds to a call about the slaughter of over a dozen people, the detective suffers a frenzied attack by the seemingly-fragile Patient Zero, before she disappears.
Now the cop has a dilemma: As a lawman, should he pursue the teen or, as he begins to show symptoms of the same uncontrollable disorder, join her and try to find a cure since the entire national security establishment is hunting them both!
More dramatic and with more character development that you'd expect for the out-of-control killer zombie-like genre, this story is at times nightmarish yet is more suspense than slasher. Plus, it segues into a storyline in the vein of Les Miz or The Fugitive: With a man on the run, unjustly-accused, protecting two young adults as he is pursued by an obsessed detective, but with a world-wide pandemic storyline thrown in.