Strangers by Candace Adams

Eleanor and Jack Harvey just celebrated their 25th anniversary. On what should have been a perfect night, Eleanor receives a message from a voice from her past.
Over the course of a few months, the mysterious stranger ups his game to a deadly obsession and their happy life together takes a heinous turn for the worse.
Stalked, followed, threatened, tormented, Eleanor’s life spirals out of control while her elusive stalker gets closer and closer. He seems to know her only too well and is always one step ahead. Will Eleanor uncover the truth behind this obsessive stranger before it is too late? Or is he really much closer than she thinks?