Richard is a murderer, starting his career as a boy killing his father in a carefully planned "accident". He is extremely clever in creating false evidence; in one example, he hurts himself deliberately with a knife after beating two foster brothers so they will get in trouble for severely hurting him. He falls in love with a woman (Jessica) but leaves her no personal space to live. She tries to escape a few times, but he eventually finds and kills her. Then he takes over the identity of another man he has watched for some time before killing him. He meets Julie by chance and is stunned by her resemblance to his first wife. He wants to "own" Julie out of obsessive love.
Julie had married her first husband, Jim, as he was the one and only man she ever loved. His sudden death drove her into despair. Before Jim's death, he made an arrangement with a friend to give Julie a Great Dane, a dog that Jim had always wanted to own. She names him Singer and he joins her life acting more and more human. After a while she starts to date men again but is still deeply unsatisfied by their behavior and character.
Mike is good friends with Julie and was also friends with Jim but is like a brother who is not eligible for dating. He feels he cannot ask Julie out due to his previous relationship with their family. He dislikes and believes he cannot compete with Richard. Singer is the title character and the catalyst in the story. He pushes the relationship of Mike and Julie, sensing that Richard is not as he seems.