“But down in the underground, you’ll find someone true…”

If you were an adolescent in the early 1980s, you probably heard tales from a college your friend’s brother’s cousin attended on the fringes of wherever you lived: a kid obsessed with Dungeons and Dragons had lost his mind and then lost himself in a maze of tunnels underneath the campus. You may have seen an exploitative novel based on the legend or, more likely, you watched a campy TV-movie based on the book. For most of us, these stories were as enticing—hey, where can I explore some steam tunnels?—as they were elusive. Thanks to a 1985 bestseller by the guy who solved the real-life case, we now know that the truth was weirder than any legend, with an emotional dimension that’s troubling, and illuminating, 40 years later.

In August 1979, James Dallas Egbert III disappeared from his dorm room at Michigan State. The 16-year-old was a clever chemist and a computer whiz at a time when almost no one had seen a personal computer. Awkward, immature, and small for his age, Egbert sought solace in every subculture on campus, desperate to belong but unable to become anything but a curiosity to older students, including sketchy acquaintances with agendas of their own. When college officials were baffled by the disappearance and the press dwelt on a possible Dungeons and Dragons connection, Egbert’s distraught parents called William Dear, a private investigator from Texas who would disclose the full story five years later in The Dungeon Master, a true-crime yarn that’s probably more compelling today than when it was first published.

To read The Dungeon Master now is to be thrown back to a freewheeling time when college students were reckless proto-adults and their daily lives simply weren’t the concern of administrators, when every crevice of a campus wasn’t monitored and mapped. Being a fan of fantasy and science fiction was still a fringe pursuit, and the press was already learning to pounce on any suggestion that role-playing games might lead to mental breakdowns, Satanism, or suicide. Even a campus with its fair share of quirky loners didn’t quite know what to do with children like Dallas Egbert: weird, sensitive, brilliant, creative, reckless, and troubled. As a record of the past, The Dungeon Master is an evocative read, but the book isn’t just a grim, nostalgic artifact of 1979. It’s a personal account of an adult trying to bridge cultural and generational gaps, first because it’s his job, and then because the case turns deeply personal.

At the beginning of their investigation, Dear and his assistants ponder Egbert’s fate—kidnapping? runaway? murder? suicide?—and privately stow their predictions in their wallets. In the weeks that follow, after butting heads with campus police and local cops, Dear crawls through Michigan State’s network of steam tunnels, which are more suffocating and treacherous than the legends implied. He gets unsolicited help from a Dungeons and Dragons player who flies in from California and proclaims himself an expert. He puts to good use a gay investigator from New York who has fallen in love with Dallas Egbert based on media reports. To understand Egbert’s mind, Dear gets so implausibly immersed in a D&D game run by a college kid that he loses his sense of self. A mysterious woman stalks Dear’s room while he’s out investigating the case, strange phone calls and notes hint at sinister conspiracies, and reporters camp out in the hotel lobby, ravenous for news.

If you’re intrigued by the case of Dallas Egbert but haven’t heard how his disappearance concluded, don’t seek out spoilers; just read Dear’s book. Despite his reputation as a James Bond character with fancy gadgets and a private jet and despite his later, lurid involvement in the O.J. Simpson case and the “Alien Autopsy” TV show, Dear writes with unusual tenderness about the missing child. This book, and the case that inspired it, turned Dear into a celebrity sleuth, but amid all the exploitative acquaintances, weirdos, hangers-on, and media hounds that gravitated toward Michigan State in the autumn of 1979, the logical, hard-nosed Dear comes off as the only one who sees Dallas Egbert as a human in full.

Dear’s account of Dallas Egbert’s disappearance serves an added purpose in the early 21st century: It’s a guide for how to remain rational, sane, and empathetic in the midst of a moral panic. It’s not a major spoiler to tell you that the Dungeons and Dragons connection, highly marketable when The Dungeon Master came out in 1984, proves to be slight, but Dear’s professional insistence on not judging the various underground movements of 1979 highlights a contrast between then and now. All of the subcultures in Dallas Egbert’s life—computer programming, the LGBT scene, role-playing games, science fiction and fantasy fandom, and neopaganism—have since been corporatized, commercialized, and entrenched in the mainstream. Superficially, that may be progress for kids who used to be different or odd. Perhaps it also means that if a 16-year-old prodigy were feeling lonely and lost on a college campus today, entrenched interests would claim their piece of him without a care for his welfare or his individuality. When everything is mainstream, when attractive and popular kids are programming computers, immersed in role-playing games, fluent in comic books, writing the rules and setting the boundaries, what becomes of the kids who still can’t fit in? Dear’s book made me wonder who we’re missing. Where are their steam tunnels, real or imagined? Where do they go when they’re tired of being told how to be?