By Jon Waterhouse

For the AJC

The midafternoon sun beams through the front door of Netherworld Haunted House in Norcross. Yeah, vampires may still be crashing in their coffins, but Ben Armstrong is a step ahead of these creatures of the night.

The co-founder of Netherworld is busy putting the finishing touches on the award-winning haunt’s latest installment. All of the lights are on, and the mechanical effects are running full blast to see what’s working and what’s not. Robotic snakes slither, faux smoke wafts through the air, giant animatronic monsters rage from above.

It’s difficult to hear Armstrong over all of the terror-tinged noise ringing through Netherworld’s winding halls. But the boyish grin stretching across his face says it all. As the attraction enters its 15th year, Netherworld is once again ranked among the top five in the nation by industry expert Hauntworld.com. Despite the long hours and looming deadlines, Armstrong couldn’t be happier.

Yet occupying the top of Atlanta’s haunted heap brings pressure.

“You have to try and top yourself each year,” Armstrong said, “but that’s also the joy of it. Why do this if you don’t have the chance to create something cool and new? We come back at it every year, and it seems like we spend more time, effort and money, anything we can to get it to be better. We just feel constantly challenged.”

One product of those challenges is this year’s new themes. Netherworld consists of two haunted attractions: The headlining haunt, the Nightmares, takes place upstairs, while Raw Meat occupies the basement area.

Although the Nightmares has a complex story line attached, the basic theme focuses on a group of creatures that can take the form of your worst fears. That means creepy clowns, spiders, snakes and just about any phobia imaginable.

Raw Meat takes guests on a tour through the underbelly of a city where hidden urban terrors reside. It’s also where most of Netherworld’s new additions can be found. Guests hop on a simulated ride in a runaway subway car, cross a suspension bridge above a pool of gators and pass an infestation of hissing cockroaches, among other frights.

“Downstairs is more industrial, bloody and intense,” Armstrong explained. “Upstairs is more classic, traditional, gothic and fantasy-based. If upstairs is ‘Lord of the Rings,’ downstairs is ‘Saw.’”

To bring the scares to life each night, it takes a crew of 100 to 120 actors. That’s not including a tech crew keeping an eye on the effects. Armstrong said he’s lost count of all of the effects running inside Netherworld. It’s somewhere between 200 to 300 different gags.

That isn’t just limited to bigger boos like the 17-foot-tall monster or the spinning vortex tunnel. Netherworld’s attention to detail remains as meticulous as ever, from projections of tiny spiders crawling across the wall to subtle scents pumped into the air.

“We do the little things because people enjoy it,” Armstrong said. “I have this thing I call the 80-20 rule. Eighty percent of the people who come into a haunted house just want to get scared and have a good time. Twenty percent of the people love the little details. They’re immersed in looking at that subtle touch. If you’re going to do a haunted house 100 percent, you’ve got to do it all.”

Doing it all means a yearlong commitment. Even before this season wraps, Armstrong and his cohorts are dreaming up ideas for next year. When the dust settles in November, the Netherworld crew will immediately begin organizational work for the 2012 edition.

But Armstrong isn’t complaining.

“It’s great to have a job that began as a hobby and something you did for fun, and it’s become a career,” he said, again smiling. “You can’t ask for more than that.”

7-11 p.m. Sundays and Nov. 4 and 5; 7 p.m.-midnight Fridays and Saturdays in October, and Oct. 31; 7:30-11 p.m. Mondays-Thursdays. $22 for the Nightmares; $28 for the Nightmares and Raw Meat; $50 speed pass includes both attractions with no waiting. Netherworld at Georgia Antique & Design Center, 6624 Dawson Blvd., Norcross. 404-608-2484, www.fearworld.com.