Okay, picture this:
Brain-eating zombies. But brain-eating zombies that only eat the brains of people who are asleep. Because zombies can’t dream. They have to get dreams from other people.
So, to protect themselves, people stop sleeping. But after a while, with no sleep, after an extended period without dreams, people become zombies themselves, and it’s only then that they begin to realize that the people zombies eat just die, they don’t become zombies themselves.
So they can either sleep, and dream, and die, or stay awake and become the horrors that prey on them.
(Brought to you by exhaustion and me shambling around work feeling half alive this week. :p)