Harrington, Wash.

"That door," he says with dramatic pause. "That door weighs 4,000 pounds. It's been reinforced to withstand a nuclear blast."

Peter Davenport has a radio voice, the kind of exaggerated baritone that cuts through walls and most doors, but not this one. This is solid steel and a foot thick.

It is Davenport's door, which opens into a tunnel leading below ground to what was once a nuclear missile complex here in the desert of eastern Washington.

The Air Force decommissioned the site in the mid-1960s and it sat empty for most of the time since.

Davenport, longtime director of the National UFO Reporting Center, a nonprofit clearinghouse and 24-hour hotline for UFO sightings, bought it for $100,000 two years ago to turn into his new headquarters.

Why does a man buy an old windowless missile complex deep underground, only to spend his days tracking unidentified objects flying through the sky?

Davenport doesn't have an answer. Furthermore, he doesn't need one. As a full-time UFO investigator and possessor of one of the world's most comprehensive, though unofficial, UFO databases, his life already runs counter to convention.

The center, in continuous operation since 1970, is known worldwide among those interested in UFOs: scientists as well as people surfing the Web. The hotline is posted on various UFO websites, and calls -- as many as 20,000 in a year -- come from people who believe they've seen or experienced something beyond the ordinary, potentially involving extraterrestrials.

If the case seems compelling and is a short flight away, Davenport will investigate in person. He takes written reports, records testimony and consults experts in specialty areas.

Davenport, 60, is a passionate, cerebral man with a haughty disdain for the media.

"I do not countenance fools," he had said earlier that day, almost as a warning. "The work of studying UFOs is of immense consequence to every living thing on this planet. If I sense you are wasting my time, I will be blunt."

His life revolves around a question, namely: "Are we alone in the universe or are we not?" He believes there are clues behind the monstrous door that he now faces.

He picks up a shovel. He has not been to his missile site in weeks, and 3 feet of snow blocks the doorway. He breaks up chunks and shovels them to the side.

It is 34 degrees on a late March afternoon, the sun just beginning to set over this patch of land 50 miles west of Spokane. Not a single house can be seen -- only snow and mounds of barren terrain and the occasional frozen tumbleweed like rolled-up cobwebs in the distance.

A wrenching sound breaks the silence. Davenport has pried open the door. He tilts his head, then squeezes through sideways before disappearing into darkness.

"He's not the normal guy on the street, but crazy? No. He's not crazy," Robert B. Frost says of Davenport, whom he's known for most of the last two decades. The former chief engineer for Boeing's portion of the B-2 bomber project, Frost met Davenport, a fellow techie, in Seattle.

"The guy's brilliant," Frost says. "Personally, I think he's going to prevail on this thing."

By that, Frost means time will prove Davenport correct on his hunch that UFOs represent a real phenomenon.