The Poison Tree is the debut novel by Erin Kelly. It is a suspense novel about a woman who will do anything to keep a secret for the friend who has bewitched her. The story is told in vignettes that move from 1997 to the present and back.
In the prologue, the main character, Karen, is in the grips of panic after a phone call we know nothing about, and she drives to an unknown destination. From here, the first chapter begins with her picking up Rex, the father of her child, who has just been released from prison, having served a ten-year sentence for murder. They are awkward in each other’s company, but their child is happy that everything is going to be ok. They stop by a house where they used to live.
The story flashes back to when Karen is in college, studying languages. She lives with a group of girls whose main ambition is to get married, and has a boyfriend she doesn’t care about. He breaks up with her, and her roommates plan to vacation without her. She meets Biba in the hallway and everything in her life changes.
Biba is a bohemian, an aspiring actress looking for a German coach. Karen speaks the language, and they embark on a friendship filled with parties, drugs, artistic people, and what Karen feels is freedom from her normal, dull life. Biba’s brother, Rex, tries to look out for them, but Biba is a force of nature.
Biba and Rex live in a run-down old house that used to belong to their parents. Their mother committed suicide, and their father is a movie executive who wants nothing to do with them. As the days go by, they ask Karen to move in, and they spend the summer drinking and having fun. Rex and Karen begin a relationship, and Biba begins a relationship with a young man named Guy, whom no one likes.
When it becomes apparent that Biba is bored with Guy, he tries to find a way to win her back. Rex has been trying to get their father to sign the house over to them, and one night Karen tells Guy about a stack of letters that Rex wrote to let off some steam. Guy mails one of them, and Rex’s father cuts off all ties with his children. A furious Biba takes Guy’s gun and shoots him. One of their neighbors witnesses the murder and when he turns to run, she kills him too.
Rex takes the blame for the murders and goes to jail. Biba disappears, telling Karen not to associate with them. Karen takes a job abroad just to get away, but when she returns, she finds that Biba is pregnant with Guy’s child. Biba gives birth, but soon abandons the baby and disappears in Karen’s car. They locate the car later and assume that she is dead.
In the present, Rex and Karen try to make a life together on the outside. Karen has passed off Alice, Biba’s baby, as her and Rex’s daughter for ten years and doesn’t wish to tell Rex the truth now. He continues to believe that Alice is his daughter. Karen, meanwhile, is receiving mysterious phone calls from someone who just hangs up, and she is paranoid that the press will find out who Rex is and begin to hound them again. Rex has changed his name to get away from his past, and all they want is to live a normal life.
At the end of the story, the mysterious caller finally speaks. It’s Biba, alive after all these years. She has returned to claim her child. This is the meeting Karen was going to in the prologue. She meets Biba and tries to explain that she can’t just come back into Alice’s life after ten years of pretending to be dead, but Biba won’t listen. Karen panics and then becomes angry.
She grabs Biba’s scarf and strangles her. She lets her fall, her body submerged in wet cement, and she goes back to Rex and Alice. That night she tosses and turns, but tells Rex it was just a nightmare. She is pregnant now and declares that she is a woman who has everything to lose who will do anything to protect what’s hers.
One of the major themes of the novel is that secrets can become something larger than ourselves. Karen instinctively takes on the role of mother, especially because, when Biba gave birth, she had Karen’s identification and her name was on the birth certificate anyway. Biba never bothered to change it, and so Karen stepped into that role.
She could have told Rex that the child was Biba’s, but by the time she visited him, the lie had already taken root. Believing that Biba was dead made it easier to slip into the lie long term. When Biba reappears, Karen’s panic at being found out causes her to do the unthinkable, murder a woman she used to adore.
The final few chapters of the novel keep us in suspense as we understand something big is building in the story. Karen’s secrets come back to haunt her, and she handles it in the only way she knows how so that she can preserve what she’s longed for most of her life, peace.