Mr. Mercedes

Brady’s research says that strychnine produces a terrible and painful death, and he gloats over how much Jerome’s dog will suffer and how much Jerome and his sister Barbara will suffer along with him. The more pain the dog feels, the more Jerome and Barbara will feel, and they will pass that pain on to Hodges. Brady hopes it will be enough to push the ex-cop over the edge and make him use the .38 Smith & Wesson. Then, Brady realizes that killing the dog might also give Hodges a reason to live—to hunt Brady down—and the thought gives him a migraine. He goes into his mother’s room and gets in bed with her. She asks if he wants her to get rid of his headache. It becomes evident that their relationship is incestuous.

Brady sends a message to Hodges in the Blue Umbrella demanding to know what evidence was withheld. He dares Hodges to answer.

Receiving the message, Hodges confirms his belief that the killer has been watching him. He canvasses his neighborhood, looking for anyone who might have seen anything out of the ordinary. One of his neighbors, Mrs. Melbourne, mentions that she thinks the ice cream truck driver looked suspicious, but Hodges dismisses her as a crank.

When Hodges returns home, he receives a call from Pete. It turns out that Donnie Davis—the man who murdered his wife—has confessed to also being the serial killer Turnpike Joe.

Hodges and Janey go to visit Janey’s mother, Mrs. Wharton, at her nursing home. Mrs. Wharton insists that Olivia would never have left her key in the car. She tells Hodges that Olivia called him “the nice one” but that the other one (Pete) was laughing at her all the time. Hodges feels ashamed of Pete and ashamed of himself for not realizing that Olivia had been aware of their ridicule.

Mrs. Wharton tells them that Olivia was talking to someone under a blue umbrella who convinced her to stop taking the meds that helped control her anxiety and OCD. As they are leaving, Mrs. Wharton adds that despite everything, Olivia still would never have died by suicide if it weren’t for the ghosts: Olivia used to hear the mother and baby who died in the attack crying and blaming her for letting Mr. Mercedes murder them.

Hodges drives Janey back to her apartment. He has grown increasingly attracted to her, although she is 20 years younger than himself, and he kisses her. He is surprised when she kisses him back. The kiss leads to more, and Hodges is astounded that she wants him in spite of his age and weight.

Brady is irritated and uneasy about the fact that Hodges seems to be ignoring him. As he drives past Olivia’s condo, he is shocked to see Hodges’s car: He is infuriated to realize that instead of thinking of suicide, Hodges has gone on the hunt for him.

Later, while Hodges and Janey are relaxing together, they speculate about the Mercedes killer. Based on Hodges’s 40 years of experience, he guesses that the killer is in his mid-twenties to early thirties, smart and good at fitting in, unmarried, and lives at home with a single parent. If the parent is his mother, he acts as a surrogate spouse to her, possibly in a sexual sense.

From the killer’s communications with Hodges, it is clear that he has been watching the detective. In doing so, the killer will have to have come out of hiding and expose himself, which makes him vulnerable. Unfortunately, that means Hodges’s associates may be vulnerable, too, but Hodges doesn’t think the killer knows he has been talking to Janey.

Hodges has thought of a way to use Pete’s capture of Turnpike Joe to tease out the Mercedes killer. He sends a message to Mr. Mercedes on the Blue Umbrella chat room, telling Mr. Mercedes to watch the news because the cops have just caught the real Mercedes killer. Donnie Davis has already confessed to being Turnpike Joe and is about to claim to be the Mercedes killer as well.

Enraged, Brady replies in an email full of profanity that Donald Davis didn’t commit the Mercedes killings. There was no valet key. The spare key was in the glove compartment, and he had another way to get into the car.

Meanwhile, Jerome has figured out how the killer got into the Mercedes. He explains how Passive Keyless Entry works: A person with the right gadget can capture the radio signal from a remote entry key fob and use it to unlock the vehicle. The gadget isn’t hard to build. He asks Hodges whether he ever checked with the auto theft department; Hodges didn’t. They had asked the head mechanic at the Mercedes dealership, who told them a key had been used. Hodges realizes that this mistake was downright incompetent. He and Pete had made a fatal assumption out of prejudice.

Brady is so enraged by Hodges’s reply that he buys two cans of rodent poison to kill Jerome’s dog, then kill Hodges, and finally go out with a bang in some kind of grand gesture. He turns on the radio and hears that the country’s hottest boy band is coming to town in just a few days. He decides the concert will be the perfect target. He stops on the way home and buys a pound of hamburger to mix with the poison for the dog. He adds the poison to the meat and hides it in the back of the fridge.

Hodges wakes the next morning to a call from Janey, telling him that her mother had a stroke in the night. Hodges helps Janey make the funeral arrangements, then they meet Janey’s aunt and uncle and her cousin, Holly. Janey’s aunt Charlotte is an inveterate complainer. Her daughter, Holly, is about Janey’s age and rarely speaks above a mutter.

On Sunday, Brady returns home to find his mother dying from strychnine poisoning. He can’t call 911 because there would be questions about where the poisoned meat came from. Instead, he goes downstairs and plays solitaire while she suffers a slow, excruciating death. When she is finally gone, he carries her upstairs and dumps her in her bed. Blaming Hodges for her death, he sends Hodges a death threat.