The end of the world arrives while a massive blizzard hits the city of Colorado Springs. During the storm, people begin losing their minds. These people instantly become giddy killers who laugh while they murder. Every fiendish assault on normal people is hilarious, every death a cause for hysterics. No one is safe from them. They hunt the young and old alike. They soon become known as the laughers. Ember and her family don’t know any of this yet. They, like the rest of the families on their remote cul-de-sac, have no idea that the world is on the verge of collapse or that their lives are at risk.

When one of their neighbors gets into a fist fight with another man, and does so while laughing hysterically, they know that something is terribly wrong, and they know things are changing rapidly. A brewing storm bears down on their faraway neighborhood, and another neighbor loses his mind. He effectively cuts off any hope of escape for the sane by blockading their street.

Ember and her family realize they must gather with other unaffected people to survive. Those who still have their sanity must come together to protect themselves and survive the storm. While they assemble, they don’t know there is one among them who carries a dirty secret. It’s a secret so terrible that anyone who finds out is at risk of death. This neighbor man is a serial killer, and his latest victim is also inside Ember’s house slowly putting together the pieces of her kidnapping.

A stealthy game of cat and mouse ensues and as Ember’s family tries to bring everyone together, the greatest threat of all is living further up the street plotting against them all. She is a laugher, but she is uniquely strong and can control other laughers from afar. With revenge on her mind, she watches her sane neighbors, thrilled no one knows who she has become, or that young Ember is her target. A nasty game is afoot, and on this night, most of those playing the game have no idea how far the depraved Laughers will go.