April Boyes

Four pals are stuck in a rut in adulthood: Adam has just been dumped, Lou is a hopeless party animal, Nick is a henpecked husband, and Jacob does nothing but play video games in his basement. But they get a chance to brighten their future by changing their past after a night of heavy drinking in a ski-resort hot tub results in their waking up in 1986.

A set of vipers has been taken by scientists to mutate them to make a cure for cancer. As their experiment goes awry, the vipers escape into the woods - they're not only biting people, they're actually killing people, in a little town.