After her sister's brutal murder, Maribeth moves into the same apartment building-determined to find the killer hiding behind one of its doors. Just weeks after she settles in, another woman is killed at the end of her hallway. As Maribeth digs deeper, she uncovers the building's dark history. And the more she investigates, the more the evidence points to someone disturbingly close: her quiet, charming neighbor. He's always been kind to her. Attentive. Protective. Maybe a little too much. Now he says he's in love with her. But can she trust a man who might have murdered her sister? To turn him in could make her his next victim- but to fall for him could mean losing everything.