In the early morning hours after Halloween 1988, four paper girls - Erin, Mac, Tiffany, and KJ - are out on their delivery route when they become caught in the crossfire between warring time-travelers, changing the course of their lives forever. Transported into the future, these girls must figure out a way to get back home to the past, a journey that will bring them face-to-face with the grown-up versions of themselves. While reconciling that their futures are far different than their 12-year-old selves imagined, they are being hunted by a militant faction of time-travelers known as the Old Watch, who have outlawed time travel so that they can stay in power. In order to survive, the girls will need to overcome their differences and learn to trust each other, and themselves.