Darkness Rises — Harley Tate

A week after the unthinkable, would you still have hope? With their house destroyed, the Sloane family sets off for the promise of safety in a cabin in Northern California. When a distress call comes through on the radio, young Madison is adamant: a detour to the nearby college is the only choice. 
What would you do to keep your family safe? Walter hates to risk his family's life for the sake of a stranger. But his wife and co-pilot need antibiotics and a college health center may be their best bet. Finding the strength to survive what happens next will be the hardest thing he's ever done.
 The end of the world brings out the best and worst in all of us. With the power grid destroyed and the government unable to help, the Sloanes are alone in a world losing hope. Will they survive a rescue mission or will the detour be the last stop on their journey? The EMP is only the beginning. Darkness Rises is book three in After the EMP, a post-apocalyptic thriller series following the Sloane family and their friends as they attempt to survive after a geomagnetic storm destroys the nation's power grid.