Tell No One by Harlan Coben. Eight years after the tragic death of his wife, Dr. David Beck receives a message on his computer. It's a phrase only he and his wife know. Suddenly Beck is taunted with the impossible---that somewhere, somehow, she is alive.
The Couple Next Door, Shari Lapena. A domestic suspense debut about a young couple and their apparently friendly neighbors-a twisty, rollercoaster ride of lies, betrayal, and the secrets between husbands and wives.