As the world descends into chaos, one woman will do anything to find her daughter... Shannon Grayson is a tough-as-nails long-haul truck driver. But her life is turned upside down when a massive electromagnetic blast hits North America while she's unloading cargo at the South-Central Retail Supercenter, demolishing the power grid. Now she's trapped inside the sprawling building, along with dozens of other survivors. And no one is coming to their rescue. Without power, the world outside begins to collapse. Shannon is determined to escape and find her daughter-they haven't seen each other since Shannon entered witness protection five years ago, but when SHTF her momma-bear drive takes over. But first, she must survive this ordeal... Eight hundred miles away is Dennis Sullivan, Shannon's witness protection officer, who swore to protect her and her daughter, and he's a man of his word. He'll battle through the ruins of America to reunite with them and ensure their safety. Desperation quickly turns to terror as Shannon and the others realize there's no way out of the locked-down supercenter. They'll have to depend on each other to survive. In the world gone mad, the only people they can trust-and the only people they need to fear-are each other...