The fifty-foot-high wall surrounding Manhattan was built to keep the virus out, but it can't keep Evan, Lauren, and Tyler in. Knowing there's more to the world than what's within the city wall, the three teens break free and hike the post-virus wilderness on a quest for a civilized outpost, as they encounter their worst fears, fight for their lives, and face the loss of one of their own. What they find at their journey's end is only a glimpse of the real battle ahead: can three teens save what's left of their home?