Mr. Mercedes (2014) is American author Stephen King’s first hard-boiled detective story. King is one of the most prolific writers of the late 20th and early 21st centuries, best known for his iconic horror novels like It (1986), Carrie (1974), Pet Sematary (1983), and The Shining (1977). However, King’s work crosses over into many different genres, including supernatural, suspense thriller, mystery, science fiction, and fantasy. He writes novels, short stories, and nonfiction, and his work often blurs the boundaries between one genre and another.

Mr. Mercedes is the first installment of the Bill Hodges trilogy and is followed by Finders Keepers (2015) and End of Watch (2016). Mr. Mercedes won the 2015 Edgar Allan Poe Award for Best Novel from the Mystery Writers of America and was the 2014 Goodreads choice for best mystery and thriller novel.

 A TV series based on the novel premiered in 2017.

This guide uses the 2015 paperback reprint edition published by Gallery Books.

Content Warning: This guide contains incidents of mass violence, suicidal ideation, incest, child abuse, mental illness bias, and racism—including the use of racial slurs—which appear in the source text.

Plot Summary

The novel is divided into three parts, each of which comprises two or three long chapters. It takes place in 2009 and is narrated in the third-person past tense.

In April 2009, a man who calls himself “The Mercedes Killer” (or “Mr. Mercedes”) drives a Mercedes sedan into a crowd of unemployed people who are attending a job fair. The driver kills eight people and wounds 12 more before escaping. One year later, a recently retired detective named Bill Hodges is having a rough time with retirement: His whole identity was defined by his job, and he can’t see a future for himself without it. Hodges is divorced, does not have a relationship with his adult daughter, and at times considers death by suicide. His depression lifts when he receives a letter from the killer, taunting him for his failure to close the case before retiring. The killer tells Hodges how to contact him using an online chat room called Under Debbie’s Blue Umbrella. Instead of handing the letter over to the police, Hodges decides to investigate the case himself.

Mr. Mercedes stole the car he used in the murders from a wealthy woman named Olivia Trelawney. Olivia Trelawney died by suicide a few months after the incident due to her guilt over the crime: When Hodges was investigating the case, Trelawney denied that she left the spare key in the car, but Hodges and his partner, Pete Huntley, never believed fully her and half-blamed her for enabling the murders.

Mr. Mercedes is revealed to be Brady Hartsfield, an emotionally “disturbed” man in his twenties who works as an IT technician for Discount Electronix and has a second job driving an ice cream truck around Hodges’s neighborhood. At home, where he lives with his mother with alcoholism (they have an incestuous relationship), Brady has a “control room” in the basement, activated by voice commands. There, he keeps a supply of homemade plastic explosives and cell phone detonators.

Proceeding with the investigation, Hodges contacts Olivia’s younger sister, Janey. Janey shows Hodges a letter that Mr. Mercedes sent to Olivia, inviting Olivia to contact him through the Debbie’s Blue Umbrella chat room. She hires Hodges to find whoever sent the letter.

Seventeen-year-old Jerome Robinson lives down the street from Hodges and sometimes mows the lawn for him. Jerome is a tech whiz bound for the Ivy League, and Hodges asks him how the killer might have gotten into Olivia Trelawney’s car without having a key or breaking in. Jerome tells Hodges about a gadget that can capture the radio signal from a remote key fob and suggests this is what the killer used. That night, Hodges posts a message in the chat room goading Mr. Mercedes, and Brady decides to get even by killing Jerome’s dog. He buys gopher poison and mixes it with raw hamburger meat, intending to feed it to the dog. However, while Brady is at work, his mother finds the meat and makes herself a hamburger, dying painfully from the poison. Brady ups the ante by planting a bomb in Hodges’s car, which kills Janey instead.

Determined to find Mr. Mercedes and punish him, Hodges leaves another taunting message on the Blue Umbrella site: “Missed me.” Infuriated, Brady decides to die by suicide at a boy band concert that will be attended by 4000 teenage girls. He plans to get into the concert by pretending to have a physical disability and using his wheelchair as a bomb.

After Janey’s death, her cousin, Holly, joins forces with Hodges and Jerome to track down Janey’s killer. Holly and Jerome find audio files hidden on Olivia’s computer and the program that Mr. Mercedes used to play the files remotely and convince Olivia that the ghosts of the Mr. Mercedes victims were accusing her of complicity in their deaths.

Realizing that the files had to have been planted by an IT specialist, Hodges learns that Olivia used Discount Electronix when she needed help with her computer. The IT team at Discount Electronix consists of only three people, and one of them, Brady Hartsfield, matches Hodges’s profile of the Mr. Mercedes killer. At Brady’s house, Hodges finds Brady’s mother’s decomposing body and Brady’s basement computer control room. While Holly searches for the computer passwords, Jerome checks the Blue Umbrella site and finds a message from Mr. Mercedes telling Hodges, “So long and enjoy your weekend.”

Hodges thinks the message means they have two days to find the killer before he strikes again, but Jerome remembers that his sister and mother are going to be at the concert that night. Hodges calls a friend in the security department at the venue and tells him to look out for a possible child molester, but the friend doesn’t think a child molester would really try to get into the concert. He tells Jerome it is safe for his mother and sister to attend.

Holly finally gets access to Brady’s computers. While she and Jerome search the hard drives, Hodges finds the leftover makings of Brady’s bomb. Meanwhile, Holly and Jerome find an email confirming Brady’s ticket to get into the concert. They rush to the concert venue, but the audience is already seated, and the concert is underway. To make matters worse, Hodges realizes he is having a heart attack and won’t be able to take Brady down himself.

Holly figures out that the only way for Brady to get in would be to pose as someone with a disability. That means he will be seated in the handicapped section. Holly comes up behind him and shatters his skull with Hodges’s “Happy Slapper,” a sock filled with ball bearings. Brady is not dead, but he is incapacitated.

As a reward for their service, Holly and Jerome are given the keys to the city. Hodges survives his heart attack, and he isn’t prosecuted for his unauthorized investigation of Mr. Mercedes. He goes to work as a skip tracer for a bail bondsman, assisted by Holly.