It continues the story of the sixteen-year-old sociopath who has now killed two demons and summoned another to his small town; in this novel, John encounters new threats, a new relationship, and heartbreak as he works to protect his friends and family from these supernatural beings.

[4] Wells has said that following up I Am Not a Serial Killer improved his abilities as a writer, particularly because of the work involved in deepening the character of John Cleaver.

On the first day of school, John learns that one of his classmates took her own life by slitting her wrists - the same exact way another girl had killed herself a few months prior.

While John and Marci are at the homecoming dance, the killer sends him a message - delivered by a student dressed in a fake bomb - in which he or she vows to "purify" the town "by fire."

After spending plenty of time together, the two grow closer, with John feeling surprised that she still wants to be his friend after learning about his sociopathy.

"[9] Publishers Weekly echoed approval of the protagonist and added, "Wells lards his fanciful narrative with enough mortuary science to ground it in the cold realities of forensic pathology and give it a grisly edge.

"[10] David Pitt for Booklist recommended I Don't Want to Kill You to "horror and fantasy fans of all ages," likening the series to Jeff Lindsay's Dexter novels.

[12] A Fantasy Book Review writer agreed that the final reveal was unsurprising, but still dubbed the novel "a great conclusion to a brilliant debut series.

"[13] Emily W. Jensen for Deseret News complimented I Don't Want to Kill You's juxtaposition of horror with uplifting story elements, saying, "Wells deftly entwines lessons on strengthening relationships, standing for what’s right, and even sacrificing for love, all while taking the reader on a roller-coaster ride of a story that surprises, scares and above all, satisfies.