The Killer's Cousin

The Killer’s Cousin is a young adult thriller by Nancy Werlin. First published in 1998 by Delacorte, it tells the story of an acquitted murderer who sees his cousin is the far more dangerous member of the family, even if no one will believe him. The book won both the 1999 Edgar Award for Best Young Adult Novel and the 2001 Maryland Black-Eyed Susan Award. Werlin is a bestselling fantasy and thriller writer for young adults. She’s known for atmospheric writing and combining both supernatural and realistic elements into her stories.

The protagonist is David Yaffe, a seventeen-year-old boy living in the U.S. David has a troubled background, and he’s hoping to start a new life for himself. A year ago, he was convicted of the murder of his girlfriend, and the prolonged trial attracted the attention of the whole nation. Only recently, the jury acquitted him. They said the death was an accident, and David is now free to get on with the rest of his life.

However, David doesn’t have many places to go. He’s missed so much high school because of the trial that he can’t graduate, although his peers have all recently finished school. What’s worse, everyone secretly suspects he got off with the murder because his father is a high-profile public figure. He goes to stay with his aunt and uncle in Cambridge, Massachusetts so he can finish his senior year at a prestigious school where he shouldn’t have any other distractions.



Aunt Julia and Uncle Vic have their own problems. The family recently experienced another tragedy—the death of Kathy, their daughter. She killed herself, and no one understands why. She lived in an apartment inside the family home, and it’s here that David will stay for the rest of the year. The couple also has a young daughter, Lily. She’s only eleven, so David knows he won’t have anything in common with her, but he’s happy to get away from everything.

When David arrives at their home, it’s quickly obvious that something is amiss. Aunt Julia and Uncle Vic are barely on speaking terms, and it seems they can’t deal with their own grief. This only makes David feels worse, because it makes it impossible to escape how badly he feels about his girlfriend’s death. When David meets Lily, she acts as if she loathes him, and suddenly David feels lonelier than ever before.

David tries to focus on school, but his home life makes this difficult. Lily is endlessly cold towards him, and his aunt and uncle barely speak to him. He notices that Lily doesn’t have any friends, and she spends most of her time alone. However, she doesn’t lock herself away in her room. Instead, she creeps around the house, moving things and sneaking up on David. She almost feels like a ghost to David, because she spends so much time in the shadows.



David suspects there’s something wrong with Lily, and he assumes it’s because of Kathy’s tragic death. He doesn’t want to bring up her behavior, because he doesn’t want to look like a troublemaker. However, she starts breaking into David’s space and destroying his belongings. She vandalizes his music, throws trash everywhere, and deletes his important school files from his computer. David is at his wit’s end. However, his aunt and uncle don’t notice, because they’re busy fighting with each other.

Eventually, Uncle Vic notices that David is struggling to fit in. He does what he can to make David feel comfortable and safe. David doesn’t want to tell him about Lily’s behavior, because he doesn’t want to get pushed away. However, her antics worsen, and she becomes increasingly erratic. David is convinced that she’s psychotic, and he’s fearful in his own room every night.

It’s at this point that Kathy’s ghost starts haunting David. She wants David to help Lily process her grief because it’s the only way she can move on. David thinks that Lily is beyond his help, and he worries that he’s also delusional because he’s seeing a ghost. Kathy tries to communicate with him to show him what happened to her, but David blocks her out.



Finally, David gets the truth out of Lily—she killed Kathy. Like David, she’s feeling guilty and angry with herself for killing someone she cared about, even if it was an accident. David can relate to this, and he decides he wants to help her. He promises not to tell anyone, but she must start dealing with her pain and stop tormenting him.

David goes out one evening and returns home to a burning house. Lily set fire to herself for killing Kathy; she can’t live with the guilt. David saves her, and this helps him get over his own feeling of worthlessness. Now, the family must all start afresh and move forward with their lives. David doesn’t see Kathy’s ghost again.