A Stranger in the House by Shari Lapena

Karen and Tom Krupp are happy—they’ve got a lovely home in upstate New York, they’re practically newlyweds, and they have no kids to interrupt their comfortable life together. But one day, Tom returns home to find Karen has vanished—her car’s gone and it seems she left in a rush. She even left her purse—complete with phone and ID—behind. There’s a knock on the door—the police are there to take Tom to the hospital where his wife has been admitted. She had a car accident, and lost control as she sped through the worst part of town… Read more.