PONTIAC, MI – Every year, about 500 people chicken out.

The fear, irrational but inescapable, overcomes them and they fail to walk through the entire labyrinth of horror at Erebus.

Another 70 or so wet themselves.

A digital counter at the end of the 2,600-foot terror course keeps count of the wimps, wetters, pukers and fainters.

MLive named Erebus Michigan's best haunted house last year.

Erebus 15 Gallery: Erebus

Brothers Ed and James Terebus, who’ve been in the Halloween hair-raising business since the 1980s, are always looking for a new way to target a common phobia.

“I’ve got things that’ll grab you, bite you, land on top of you,” Ed Terebus said. “I’m gonna put you in a room, slam the door, bury you alive, fill that room up 6-foot-6 – how long can you hold your breath? You can’t find that stuff at any other haunt.”

The operation started inside trailer setups at strip mall parking lots, charging $1.50 for a scare.

Today it’s an elaborate, permanent setup in a 113,000-square-foot building in Pontiac charging $23 to $40 a person.

The thrill-seeking masses will start waiting in line, reserving time slots and throwing money at the Terebuses a week earlier than normal this year, with the house set to open on Friday the 13th.

“It’s a lot of fun. I love being scared, but it’s a lot more fun scaring people,” Ed Terebus pointed out tricks and safety precautions while his crew made final preparations a few days ahead of the opening.

In addition to old-fashioned masks, make-up and stuffed evil monkeys, the Terebus brothers have developed ways to use pneumatics and phosphorescence to create disorienting illusions playing on deep-rooted, natural human anxieties like falling, being eaten and – new this year – clowns.

They draw inspiration from wherever they can find it. Ed Terebus came up with the haunted house's name while reading a vampire novel and discovering that his last name minus the T, Erebus, matched the name of a god of darkness in Greek mythology.

“We eat, sleep and drink haunted house stuff,” he said. “It’s a never ending process… This is a passion over here. It’s an obsession… There’s an energy in here that you can’t even imagine.”

The haunt runs on the continuous theme of a mad scientist who’s created a time machine that transports its human guinea pigs through various realms of terror, ranging from ancient Egypt and a prehistoric swamp to a zombie war zone and an alien circus.

Something in the air as autumn approaches compels people in Michigan to obsessively seek out a fearful experience, said Terebus, who also runs Fear Finder, a popular annual newsletter that maps out the region's haunted houses.

“It’s the change of season,” he said. “It’s the cooler air. You’ve got to find the biggest and the best one. Michigan is a Mecca for haunted house goers.”

Follow MLive Detroit reporter Khalil AlHajal on Twitter @DetroitKhalil or on Facebook at Detroit Khalil. He can be reached at kalhajal@mlive.com or 313-643-0527.