Imagine a young woman driving north, headed for New England’s White Mountains, a troubled personal life in Amherst, Massachusetts, in her rearview mirror. Mainly, it’s small tragedies that preoccupy her: a breakup, some minor credit-card-fraud charges, crashing her dad’s car. Many people hit a breaking point in their lives. Maura Murray’s came on February 9, 2004. She was twenty-one years old.

Murray probably took I-91 north that day, having packed up her dorm room at the University of Massachusetts and printed out directions from MapQuest. She didn’t tell anyone her plans. Around 7:45 P.M., she fell off the map. Forty-five minutes earlier, she had driven her car into a snowbank along a smaller highway near Haverhill, New Hampshire, not far from the mountains. A neighbor saw the car there, and a person pacing outside it, and called 911. A school-bus driver stopped and talked to Murray, just for a moment. She begged him not to call the police; AAA was coming, she said. She was in sufficient distress that the man called the police anyway when he got home.

The cops arrived at the scene soon afterward. The car was still there, but Murray was gone. There were no footprints leading away from the scene that could have helped them follow her, wherever she had gone. The area was lightly populated, and the neighbors hadn’t seen her leave. A box of wine had spilled all over the interior of the car. Murray’s belongings were still in there, too, except for her wallet. No one ever heard from Murray again.

If you are, like me, an insomniac prone to reading Wikipedia’s crime section at night—and I have found this to be a fellowship with a wide subscription—you have probably come across Murray’s story before. It is not a particularly famous case in the annals of American crime: it never generated a national media frenzy or fixed Murray in Americans' minds the way that, say, JonBenét Ramsey was. Still, Murray was young, white, and attractive, attributes that tend to drive a lot of interest in missing-person cases. And there is something haunting about the way she vanished—how, just as she seemed to want to check out of her life, it actually happened. It’s Gone Girl before “Gone Girl,” the sort of narrative hook that can suck a reader into a novel. In the chaos of the real world, the people who got drawn into Murray’s story, other than her horrified and grief-stricken friends and family members, were a bunch of strangers on the Internet.

The dizzying pull of a real-life mystery is nothing new. Nineteenth-century newspapers trafficked in amazingly detailed accounts of murders and careful reporting of trials that invited readers to parse the evidence themselves. Pulp magazines like True Detective later sprung up to take their place. A lot of American fantasies are built around a life spent solving crime. When Truman Capote went with Harper Lee to Kansas to report “In Cold Blood,” he was simply doing what many others had dreamed of. The frenzy, in 2014, surrounding “Serial,” a podcast that investigated an old murder case in Baltimore, was built on the same cultural foundation. And, ever since its wild success, it seems as though we’ve had one true-crime craze after another packaged and sold to us, with networks and producers itching to find the next Adnan Syed, from “Serial,” or Steven Avery, the subject of the Netflix series “Making a Murderer.”

So it is not surprising that an early review of James Renner’s “True Crime Addict: How I Lost Myself in the Mysterious Disappearance of Maura Murray” would call the book “an entrancing, brilliant next step for fans of the podcast Serial, Netflix’s Making a Murderer, and other true crime cases.” Published last month by Thomas Dunne Books, an imprint of St. Martin’s Press, “True Crime Addict” is a strange beast—one that embodies every problem that arises when online obsessives are infected with delusions of detective grandeur.*

The book follows Renner as he tries, over a number of years, not simply to report on but to actually solve, personally, Maura Murray’s disappearance. Renner, who was a reporter for an alternative weekly in Cleveland until he was fired, in 2009, has no particular connection to the case other than an apparent obsessive streak that previously was laser-focussed on the disappearance of a ten-year-old girl named Amy Mihaljevic. In the book, Renner writes, without any evident self-awareness, that he fell “in love with Amy Mihaljevic when I saw her MISSING poster hanging on a utility pole when I was eleven years old.” He wrote a book about her before he fastened onto Murray.

Like most of us, Renner encountered Murray’s case many years after her disappearance, on the Internet. Unlike most of us, he promptly set up a blog and started publishing his “findings” there. He did some shoe-leather reporting, going out to the crash site and visiting witnesses’ houses. Almost everyone slammed the door on him or else granted only limited interviews. The people who did not block his way, who wholeheartedly embraced his methods of pursuing the case, were other people on the Internet: the commenters on his blog and the people who e-mailed him tips—rarely anonymously, but never with any real connection to Murray. And, perhaps because those were the people who accepted him, Renner embraced them in return. He posted rumors sent his way, including some that were scurrilous or unhelpful.

About halfway through the book, Renner delivers a kind of soliloquy about his journalistic methods: