A Stranger in the House (Used Book) - Shari Lapena
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.
The accident has left Karen with a concussion and a few scrapes. Still, she's mostly okay--except that she can't remember what she was doing or where she was when she crashed. The cops think her memory loss is highly convenient, and they suspect she was up to no good.
Karen returns home with Tom, determined to heal and move on with her life. Then she realizes something's been moved. Something's not quite right. Someone's been in her house. And the police won't stop asking questions.
Because in this house, everyone's a stranger. Everyone has something they'd rather keep hidden. Something they might even kill to keep quiet.