The dogs
The dogs are a symbol for Morgan's own animal instincts. She loves the dogs in a way she can't manage to love herself, but the dogs are avatars of herself by loving her enough to do what she isn't willing to do. They attack, murder, and mutilate the man who abuses her. This sets off a chain reaction that causes her to investigate her relationship to him and to herself, and in the meantime, the dogs are killed for their sacrificial action.
The sociopathic fiance
Bennett is a symbol for the ways that people victimize people who are looking for love. It is normal and natural for Morgan to want to believe the best about her suitor, and the online romance makes it easier to ignore red flags. But, in the end, she realizes that she has ended up with a crazy person who lies for fun, and about whom she knows absolutely nothing—except that he is abusive when he arrives to live with her.
The Radiohead allusion
There is a funny allusion to Radiohead, because Bennett claims that he played bass for the band. This is a symbolic allusion, because it signals that Bennett is skillful at manipulation. Morgan loves Radiohead, so she wants to believe she's dating the Bassist, but in reality, she could have just searched online—the band's membership history is public. The lie represents the thinly veiled deception that she was willing to fall for.
Therapy as a symbol
Therapy is a symbol in the novel because of what it means to her in the context of the story. Morgan has not protected herself whatsoever, and even though the dogs "took care of him," so to speak, Morgan has to determine why she allowed herself to be in bed with a sociopath. Therapy is a symbol for her responsibility to undertake that investigation with sincerity and self-approval. By going to therapy, she admits to herself that she is worth protecting.
Morgan's thesis
Morgan's thesis is paralleled with the events of her life with strange synchronicity. This is because the thesis represents her mastery over the psychological issues that plague her. One could say, "The sociopath is to blame for that," but Morgan admits to herself that if anyone should be able to spot a sociopath, it's probably her, since she is literally in Grad school to study criminal psychology. Her thesis represents her responsibility for the knowledge she learns. The synchronicity brings her knowledge off the page and into her real life.
