The Kind Worth Killing is a 2015 psychological suspense novel by Peter Swanson. Peter Swanson is a thriller novelist, specializing in mystery and suspense novels. The novel follows Lily Kintner, who meets Ted Severson in an airport bar and convinces him to murder his wife, Miranda. Through backstories and unexpected character developments, Swanson explores themes of Moral Ambiguity and the Justification of Murder, Power Dynamics and Manipulation in Relationships, and The Lasting Effects of Trauma.

This guide refers to the Faber and Faber 2015 print edition.

Content Warning: This guide includes references to the source text’s description of sexual assault and molestation of a minor.

Plot Summary

Ted Severson meets Lily Kintner at Heathrow Airport. Ted tells her that he just found out that his wife Miranda is cheating on him with a man named Brad Daggett, the contractor for their new home in Kennewick, Maine. Lily suggests that he should murder her. Lily explains that she has a unique morality system and that she justifies murder when a person seems to only bring negative energy into the world. Rather than considering it murder, Lily believes that Ted would only be speeding up Miranda’s inevitable death while ridding the world of a harmful person.

Lily has a flashback to when she was a child at Monk’s House in Connecticut. When she was 13, a painter named Chet stayed in their house. Chet gave Lily a bad feeling, and she tried to stay away from him. During one of her parent’s parties, when Chet finds Lily alone, he molests her.

In the present, Ted sits next to Lily on the plane, and Lily tells him that she will help him murder Miranda. They agree to meet at a hotel in a week if they both still feel committed to the plan to murder Miranda. This development causes Lily to reflect again on her past.

Lily experiences another flashback to Monk’s House and remembers how she decided to punish Chet. After a few weeks, Lily lures Chet outside to a meadow behind their house. She leads him to a well, and when Chet looks in the well, she pushes him in. Lily’s parents think that Chet left in the middle of the night, and they never talk about him again. Lily is relieved to have gotten away with the murder of her predator.

A few years after Chet’s murder, Lily attends college. Lily starts dating a boy named Eric Washburn and befriends Eric’s previous girlfriend Faith. After Eric graduates, he continues to date Lily, but Lily finds out that he is cheating on her with Faith. Lily studies abroad in London, and when Eric comes to visit her, she murders him by slipping nuts into his food and hiding his Epipens.

In the present, Ted meets with Lily and they both agree to go through with the murder. Ted and Lily meet in a cemetery, and Ted kisses her. Over the next few weeks, as they plan the murder, Ted decides to divorce Miranda instead of murdering her because he falls in love with Lily. He realizes that he can be with Lily and Miranda can be with Brad, and no one needs to die. Later that day, Brad arrives at Ted’s house unexpectedly. Brad enters and murders Ted.

Lily learns about Ted’s murder and suspects Miranda. It is revealed that Lily was manipulating Ted to murder Miranda, who is in fact Faith—her college boyfriend’s ex-girlfriend—because Miranda encouraged Eric to cheat on Lily. Lily travels to Kennewick and finds Brad. She tells Brad that she will tell everyone that he murdered Ted unless he helps her murder Miranda. Conversely, Brad tells Miranda about Lily and how she wants to murder her. Miranda suggests that they go along with Lily’s plan, but when Brad is supposed to kill Miranda, he should kill Lily instead.

Detective Henry Kimball interviews Lily because Miranda suggested that she may have known Ted. After the interview, Lily drives to the Severson house in Kennewick and waits for Brad and Miranda, unaware of Brad’s alternate plan. When they come inside, Brad, having convinced both women of his alliance, murders Miranda instead of Lily. Afterwards, Lily and Brad sit in his truck and Lily drugs Brad. When Brad is unconscious, Lily strangles him. Then, Lily drives Brad’s body to Monk’s House and hides his body in the well.

The police discover Miranda’s body. Kimball cannot stop thinking about Lily as a suspect. He learns about Eric Washburn, who Miranda and Lily both dated, and he starts to suspect that Lily had something to do with his death. Even though he has no evidence, he starts trailing Lily. Lily returns to the cemetery where she and Ted kissed. When Kimball is distracted, Lily stabs him. Kimball’s partner arrives at the scene and arrests Lily. A few days later, Lily’s attorney tells her that she does not think Lily will serve time because Kimball was acting outside of the police department when he followed her. Lily makes up a story about how she is afraid of Kimball, and this helps her case. The attorney leaves Lily with a letter from her father. Lily reads the letter, where her father explains that someone bought the meadow behind their house and wants to build a house on the land. They are going to level the land, and Lily realizes that the workers will discover the bodies in the well.