From the air, there was nothing to see but the firefly dance of the fluorescent yellow light sticks waving the Marine chopper down until it settled in a bowl of fine, talcum-like dust.

The passengers disembarked from the back of the CH-46 Sea Knight and immediately plunged into the dark territory ruled by the Night Walkers, the Marines responsible for the helicopter landing zone at this military outpost in western Iraq.

The Marines fly primarily at night, so that's when the Night Walkers go to work. Like bats, they wake up as the sun sets, shaving and brushing their teeth at a portable water tank parked in the mud. By sunrise, they are tucked into their racks.

Out on the flight line, the Night Walkers have no running water, no chow hall, no one but each another. But on a clear night, they have a sky filled with stars.

"At night here, no clouds, when you can see the Milky Way, it almost kind of makes you forget where you are sometimes," said Staff Sgt. Randal Southern, 29, a reservist with Marine Air Control Squadron 24, based in Fort Worth.

Where they are is one of the most dangerous U.S. military camps in Iraq, a Marine outpost near a city that the military may storm and retake from insurgents and foreign fighters if the interim Iraqi prime minister gives the word.

In the larger Marine camp, which the Night Walkers call town, Marines and soldiers have been gearing up for battle in recent days, cleaning their weapons, drilling, lining up at the barbershop for haircuts, turning in a last load of laundry and stocking up on cigarettes, foot powder and cases of soft drinks at the Post Exchange.

Southern said the Night Walkers sense a military operation may be imminent because of the increase in flights at the landing zone, where 16 helicopters, or "birds," as the Marines refer to them, landed one night recently during a four-hour period.

"There's been a lot of pushing out and pushing in," he said. "It still feels like we're being a part of the fight or close to it."

The landing zone is home to three controllers from the Marine Air Control Squadron and a small detachment of land support Marines from the Combat Service Support Battalion, known as "red-taggers" for the red bar worn on their pant legs, an identifier first used in World War II to help Marines coming ashore find someone in charge.

"I like being out here, away from everyone and everything," said Staff Sgt. Thomas Purnell, 32, a member of Combat Service Support Company 115, which provided the land support detachment. "We have a job to do. We get it done, and nobody bothers us. You kind of feel safer out here, away from everyone else."

On Tuesday night, just before dusk, as the hues of the sky moved from light purple to dark blue, Lance Cpl. Dustin Oppert, 20, of Grand Prairie, Tex., walked across a mud field to flip on the radar, signaling the start of the night shift.

"It's quiet here," said Oppert, a member of the Marine Combat Service Support Battalion 1. "You're not dealing with people walking around. We like our solitude. We have the luxury of going into town if we need to, if we need real people, our social fix. That's what we call it, 'town.' Like we're in the country."

Although a bird will land here occasionally during the day, most helicopters arrive in darkness. The pilots must rely solely on sight to guide the aircraft to a strip of asphalt lined with blue lights.

There are no other lights on the landing zone, and at night, even the larger camp is largely plunged in darkness. Marines walk around in the dark, their boots somehow managing to find the terrain. This absence of light makes the camp feel like a black-and-white movie, with grainy, shadowy figures that abruptly appear and disappear.

"We have to talk some pilots into getting here," said Southern, an engineer in civilian life. "We've had pilots make two to three passes before they find us. Our job is to make sure the pilots get on deck safely. It's like being a traffic cop."

The air traffic control tower is the roof of a single-story, concrete building at the landing zone that serves as an office and sleeping quarters. To reach the top, the Marines climb a handmade wooden ladder braced against a broken drain pipe. The controller uses a portable radio and a small electronic weather gauge that hangs on a string and resembles a stopwatch.

Out on the flight line, Lance Cpl. Andrea Hopkins, 21, of Everett, Wash., talked into a yellow hand-held radio and prepared a group of passengers to board the second of a pair of CH-46s coming in from Baghdad.

"I tell my mom it's not as bad as it seems," Hopkins said after the helicopters took off in a rumble of noise and a swirl of dirt.

And out here, in this corner of the outpost that Purnell calls "heaven," it certainly feels that way, particularly on a night like this, when the air is crisp, the booms of the outgoing artillery rounds are off in the distance and the clouds, full of rain, fail to deliver.

Marine Lance Cpl. Andrea Hopkins, 21, of Everett, Wash., coordinates the arrival and departure of passengers on a CH-46 helicopter near Fallujah.