The door to the freight entrance unrolled like a steel curtain and closed with a clunk, sealing Lance Maeda inside the warehouse with the ghost hunters. The quiet of its 40,000-square-foot interior, some of it already in darkness, was suffocating.

Strange things happen here at DHL Express on Paiea Street, often late at night when the place is nearly empty, like now. Delivery vans have bounced up and down with no one in them, the echo of squeaky springs rising toward the high warehouse ceiling. Van doors have slammed shut. Packages have been tossed.

Maeda, the station services manager at the warehouse and a 41-year-old Kapolei father of two, has heard the noises too many times to dismiss them. It's the reason he asked Hawaiian Island Ghost Hunters — a group that specializes in "local paranormal research" — to investigate. Maeda wants an answer, or whatever is going to pass for one.

"I cannot rationally explain it," he says, staring beyond 50 yellow vans into the gloom. "It's not just me. It's not just my morning supervisor. It happened to my evening supervisor. It happened to my couriers. We all know we are not insane. We are not hallucinating these things."

The building has been haunted ever since the shipping company moved there in 1995, he says.

Employees, Maeda included, have heard the sound of chairs being thrown around an empty conference room — and found nothing when they checked. They watched from the parking lot one night as the upstairs office blinds opened on their own. And a few years ago, the DHL security cameras even caught a van's flashing lights come to life — and a shadow of someone in its cab.

The last straw came two weeks ago, Maeda says. A courier was alone on the silent warehouse floor, sorting packages when a rapid series of pops broke the silence.

Then he heard little girls. They were giggling.

"He's not on the early-morning shift anymore," Maeda says.

'NOSKEDUM'

None of this worries the ghost hunters, led by founders Blaise Atabay and Preston Galera.

It's no accident that they are here late at night. They want conditions to be as free of outside noise as possible. They'll also have to shut off power to parts of the warehouse because paranormal researchers use sensors that detect electromagnetic fields, which typically come from lights and appliances.

That means they'll be standing in the dark looking for spirits.

But dressed in black T-shirts that boast they aren't scared of anything — "NOSKEDUMWE-GETUM" — they cheerily position four cameras with night- vision capability around the warehouse. They'll record everything for review, including what they capture on digital video recorders that can see in the dark.

If it sounds a bit whacky, they don't mind. They're skeptics, but they've seen things they can't explain, creepy, spooky things. They've listened to voices. They've felt the cold touch of something that wasn't there.

The DHL warehouse intrigued them, Atabay says. The employees had cataloged 13 incidents, or more than twice the number of claims the ghost hunters usually receive.

"It sounds like they are pretty freaked out," he says.

When the equipment is finally ready, Galera put on a miner's cap and turned on its red light. He grinned for a moment and gave the word.

The warehouse was swallowed by blackness.

"Is there anybody in here with us?" Galera asks.

From the back of the warehouse, something made a sound.

A SEARCH FOR TRUTH

On its Web site, www.HawaiianIslandGhostHunters.com, the group describes its investigators as normal people with day jobs, hobbies and families.

Atabay, 29, is an investigator with the city medical examiner's office and Galera, 31, is a branch manager for Airgas West Gaspro. They created the group about 18 months ago after watching TV shows about ghost hunters.

Both local boys, they had grown up with a healthy respect for the supernatural in Hawai'i — Atabay says his parents' Mililani home was haunted, and Galera says his great-great-grandmother was a kahuna.

They wanted to know if the truth was really out there.

"Our main purpose is to not prove a haunting or find a ghost," Atabay says. "Our main purpose is to go out and find a logical, scientific explanation for what is happening. It is easy to say you have ghosts or hauntings, but a lot of times it is just people's minds playing tricks on them."

Their group has finished eight investigations and disproved about 90 percent of the claims, Atabay says. But that doesn't mean they were alone. On every investigation, they've listened to and recorded unexplained voices, laughter, sounds and even shadows that shouldn't be there.

"I'd be lying if I said I wasn't scared," Atabay says. "When I do get scared, sometimes I think to myself that it's my mind playing games with me."

Galera says he has witnessed, but not recorded, two "full-body apparitions" while investigating claims. "I can tell you until I am blue that I saw a ghost, but can I prove it? No. It's good for telling stories, but as far as what we do, trying to prove it, we have to capture it physically on a video recorder or in photos," he says.

In March, while setting up equipment in a Wahiawa Heights home, Galera saw a silhouette of a person walk past an open doorway. At first he thought it was Atabay, then learned neither his partner nor the rest of the team was anywhere near him.

"My eyes don't play tricks on me," Galera says. "It was right in my plain sight."

He got a stronger jolt in August, when the team investigated a city basketball gym that he can't identify.

The gym was said to be haunted by spirits who would rattle one of its doors. That was easily explained: The door was loose and easily shaken when the wind blew.

No one could explain what Galera saw, though — someone or something briefly popping up from behind the bleachers. No one could identify the whispered voices that Atabay kept hearing.

And definitely none of them was ready for what happened after that.

They had positioned themselves at different locations in the gym, hoping to pinpoint the source of the voices. They stood in almost total darkness and listened hard.

That's when the bleachers started to shake violently. It was like someone was running the length of them. Atabay tried to focus his eyes in the gloom. His night-vision digital camera had stopped working.

The banging on the bleachers grew louder and closer. Everyone heard it. It was so real, Atabay braced for impact.

"My heart was racing," he says. "It was coming straight toward me. Right as the noise got close to me, it stopped."

SUDDENLY, A WHISPER

For an hour, Atabay and Galera, along with three other investigators, walked through the warehouse and its offices. They took temperature readings — it's 90 degrees — and looked for EMF changes. They asked for anything supernatural to give them a sign, but so far, every noise seemed explainable, linked often to a parking lot on the warehouse roof.

Not so for investigator Wayne Basa, who went to the upstairs offices with Gene Ganoot.

"As we came downstairs, right here, I thought what I heard was a whisper," Basa says. "When we reached the bottom, Gene looked back and he kind of saw, from the floor, a head peep out. Like a shadow."

They didn't get it on camera, though.

Among the investigators, Basa, a 38-year-old machinist who says his only fear is of spiders, is the one who dares the ghosts. So far, the tactic hasn't worked, but he's talked to Mainland investigators who say they've experienced everything from a gentle shoulder tap to being thrown across a room.

Basa says he'd welcome that.

"It would be great if I had it on camera," he says.

On the warehouse floor, amid occasional creaking sounds from overhead, Basa started with gentle questions, but quickly shifted his approach.

"Maybe this is someone trying to intimidate people by sounding like a little girl because it's weak and all they know how to do is scare people," he says. "I think you are weak."

In the darkness, nothing. Just silence.

"This thing doesn't like me," Basa says.

PARANORMAL OR PARANOIA?

After another, quiet hour, the ghost hunters gave up on this night's search. They don't think they have found evidence of the paranormal. "I think it's paranoia," Atabay says.

Still, they'll review every minute of their recordings and examine every photograph. They're not as disappointed as Maeda, who isn't sure what to make of such a quiet night. He and several co-workers huddled at the far end of the warehouse during the investigation, patiently waiting in the dark for something to happen.

As someone opened the freight door, Maeda shrugged. The night's conclusions will be hard for people to accept, and he thinks his employees will dismiss the investigators instead of the ghosts.

"If there is a logical explanation, that's OK," he says. "If not, we'll keep our minds open. Anything is possible. Give us a logical explanation and we'll give up the ghosts."