Fifteen-year-old Emma has moved house with her ex-Marine mother and younger brother. It's a brand-new condo building, which explains the semi-regular power outages, as workers complete the units around them. So Emma isn't particularly concerned when the latest blackout hits just as they are preparing to leave town on a long weekend camping trip. But then the car won't start, and their cellphones appear dead... and all the cars outside their building seem to be stalled in a long traffic jam....
In the midst of what appears to be a massive power outage, with their camping gear packed and ready, Emma and her family canoe over to the islands, just offshore, to wait it out. But while they land on an isolated island, with a relatively hidden site, they are far from safe, as people become increasingly desperate to find food and shelter. And as the days pass, and the power remains out, the threat of violence becomes all too real.