David Horton is begrudgingly beloved. He wouldn’t have it any other way.

The 67-year-old ultrarunner-turned-race-director is the mad scientist behind some of the ultrarunning community’s most reputable races, the Mountain Masochist 50 Miler (which he no longer directs), Holiday Lake 50K, Promise Land 50K, and Hellgate 100K. Over the course of his three-decade-plus ultrarunning career, Horton has logged a dizzying number of achievements—over 160 ultras, speed records on the Appalachian Trail (1991) and the Pacific Crest Trail (2005), and the third-fastest time of the Trans-America Footrace (1995), just to name a few.

By all appearances, Horton is a glutton for punishment. Even open heart surgery and a total knee replacement hardly slowed him down. Runners aren’t sure whether to admire the man or fear him. Or both.

It’s no wonder then, that adversity is part and parcel of his ultras. Impeccably organized yet relentlessly brutal, Horton’s races are relics of a bygone era, a time when race applications arrived by post and grit, not glory, made a runner great. There is still no online registration for Hellgate 100K, and should a runner DNF or fail to run her best, she should expect shame, not sympathy, from David Horton.

It’s nearing 9p.m. on Friday, December 8, 2017. Nearly 200 runners, crew members, and volunteers are crowded into a room at Camp Bethel in Fincastle, Va. In just two hours, the entire room will caravan to the start line of the 15th annual Hellgate 100K. Horton is midway through his pre-race briefing when someone asks about the course records. He turns to Sarah Schubert, the 2016 women’s winner.

“Prove me wrong. I don’t think you’ll beat the record. Even if someone beats you, I don’t think they’ll beat the record. Amy Sproston is a better runner than you.”

There’s a split second of uncomfortable silence. I’m tucked in a corner behind Horton with some of his students from Liberty University. Stunned, I wait for the “just kidding” or the punch line that will break the ice. But it doesn’t come.

“He likes to be inflammatory,” Schubert tells me a week later. “If people want to do well in Horton’s races, it takes a different type of person. You certainly don’t want to come to his races expecting to be coddled, either by him or the course.”

Horton continues to dole out tongue-in-cheek jabs that teeter between playful and crass. No one is spared. The assistant to medical director Dr. George Wortley is “a good woman, but a little strange.” George Plomarity, the Patagonia representative, “weenied out, wussed out,” and DNFed at his first Hellgate. Even I find myself at the root of some ridicule. “Daddio? That’s a terrible last name. Are you married yet? Well good, that means you can still change it.”

When it comes to Hellgate though, Horton’s ruthless candor is the least of the runners’ problems. There’s plenty to dread about this one-of-a-kind point-to-point ultra: the 12:01a.m. start at an unpredictable time of year, leaf-covered technical trail, the real threat of frozen cornea (dubbed “Hellgate Eyes”) and sleep-deprived hallucinations, 12,000 feet of climbing, and those nasty “Horton miles” that turn this 100K into a befitting 66.6 miles instead of the standard 62. Just crossing the finish line at Hellgate is a commendable feat. Many runners race Hellgate once and never return. But sitting in that room at Camp Bethel are five runners who have shown up every year since 2003, in respect of but not unfazed by Horton or Hellgate. They are the Fearsome Five.