"We used to wonder what the hell was in there," said Ed Risinger, one of the Forward Air Controllers who flew the risky missions just north of the DMZ, looking for targets. "We knew there was something inside." The "Misty" pilots, as they were called, eventually deduced that the cave hid a ferry the North Vietnamese Army used at night to shuttle war materiel across the river on its way to the Ho Chi Minh Trail and South Vietnam.

US warplanes dropped hundreds of bombs on the mouth of the cave, and in the process many were shot down. Even if an aircraft managed to survive the withering anti-aircraft artillery on the approach, it would then encounter the cliff, which rose to an imposing height. Pilots could not fly low enough to execute an accurate drop and still have time to pull up and clear the cliff face. The Air Force, in fact, never managed to close the tunnel or find the ferry. Nor did it ever figure out exactly what went on inside the perplexing hole in the mountainside.

That mystery and other unfinished business from Vietnam receded as the American role in the war ended in the early 1970s and the men who fought the war went on with their lives. But like a deeply buried splinter, it eventually worked its way back to the surface. At Misty FAC reunions, tales of engagements along the "Disappearing River" were among the most cherished of all the war stories. Finally, Dick Rutan-call sign Misty 40-decided he needed to go back to Vietnam and see some things for himself. Risinger and four other Mistys agreed to go with him. No family members were allowed. The pilots did not want to have to explain the war or their emotions. Moreover, the State Department had issued warnings that Americans could encounter hostility and violence.

So it was that, in the spring of 2000, on the kind of overcast day that would have been a bust for the Misty FACs trying to spot targets through the clouds, six former Air Force fighter pilots touring the now-Communist Republic of Vietnam boarded a sampan that took them upstream. Just a few miles away was the Phong Na Cave, where the Disappearing River flowed out of the mountain.

The Americans went around a few bends in the river, and then, suddenly, there it was-the cave. They went inside. Instead of the cramped hideout they had expected, the Mistys discovered a vast cavern spiked with stalactites and stalagmites-and filled with other tourists. "We all stood there and looked at it," said Rutan, "the beauty and majesty of it, to think what we were trying to destroy." The Mistys learned that, during the war, the cave had indeed housed the ferry-plus much more. There had been a North Vietnamese field hospital inside, with more than 2,000 patients, refugees, and soldiers. From the mouth of the cave, it became apparent that the layers of rock on top of it made it virtually impregnable. "When I think of the bombs we wasted and the airplanes shot down-it was sheer folly," said Rutan.

The Mistys didn't need to make a trip to Vietnam to grasp the general folly of the war, as it was conceived and executed by President Lyndon Johnson and his Secretary of Defense, Robert S. McNamara. The Misty FAC mission evolved from it. For most of the war, political leaders in Washington refused to allow attacks on the key targets of Hanoi and Haiphong Harbor, where most northern war supply shipments originated. Instead, Washington settled on a strategy of interdicting supplies truck by truck, as they neared the South Vietnam border under cover of night, clouds, and triple canopy jungle.

That decision led to the formation in 1967 of the Misty detachment-a group composed entirely of volunteers, flying fast and low in two-seat F-100 fighters. The unit was activated in June 1967 at Phu Cat AB, South Vietnam, a newly built facility located 20 miles northwest of the city of Qui Nhon. Their job, when they weren't orchestrating rescues of downed pilots, was to continuously scout for targets and mark them for bombers. The four- to six-hour scouting sessions made the Mistys such inviting targets that the Communist gunners gave them special attention. One-quarter of them were shot down.

The reasons for returning to Vietnam were simple and did not feature attempts at "shedding old demons" and such. "I don't think we had much of that," said Mick Greene, Misty 30. "It was just going back with these guys and reliving some of the missions that we flew." Some couldn't resist trying to acquire a final taste of the camaraderie they once felt as warriors whose lives depended on each other. "When I left [Vietnam] in 1973, it never crossed my mind that I would ever go back," said P.K. Robinson, Misty 45, who spent nine months as a POW after getting shot down in 1972. "My wife kept asking me, 'Why do you want to go back?' I said, 'I have no idea.' Rutan made a plan, and I decided I wanted to be part of the action." Others were driven by simple curiosity. Risinger, Misty 32, said, "I wanted to see what was in that cave and the Mu Gia Pass," the busy mountain crossing into Laos that was a key target for US air attacks.

Route Pack 1

Many American veterans have made pilgrimages back to Vietnam, but the Mistys were different. They had little interest in exploring Ho Chi Minh City (they still call it Saigon), Hanoi, or other urban centers of the war. They were, instead, drawn to the rugged backcountry below Route Pack 1, the 8,000-square-mile swath of North Vietnamese airspace patrolled by Misty FACs. During the war, they became intimately familiar with landmarks of the terrain. There were, in addition to the Disappearing River and Mu Gia Pass, Bat Lake, Butterfly Lake, and Pork Chop-so named for the shapes they resembled. There were also significant places that appeared on no maps-anti-aircraft gun pits known for their vicious effectiveness, mountaintops, rice paddies that had been the focus of intensive rescue operations, and sites where empty parachutes gave the last signs of fellow pilots.

For all their familiarity with the terrain, only those who got shot down had ever seen it at ground level. "I had a haunting desire to walk around on the ground and just see what it was like," said Rutan. Beyond that, he had one specific quest: To stand on the spot near the Mu Gia Pass where a fateful truck had been parked in 1968. While flying a pass over the truck, Rutan was hit by AAA and shot down and had to be rescued several hours later.

The group of Mistys had a celebrity among them-in 1986, Rutan and Jeana Yeager flew Voyager around the world nonstop, without refueling, the first and only persons to do so-but the Mistys wanted to travel the country as ordinary tourists. They found a tour operator who rounded up local guides to take them wherever they wanted to go. The Mistys asked no special assistance from the Vietnamese government and did not even identify themselves as former American military men. The only restraint placed upon them was a quirk of the Communist regime: They were to be accompanied on the trip by an official guide, and they had to give one day's notice of any area they wished to visit so that local officials could be "prepared."

The Mistys planned to stage day trips into the backcountry out of Dong Hoi, a coastal city about 50 miles north of the DMZ, but they first had to fly to Saigon and navigate their way north. They arrived apprehensive. It was nearing the 25th anniversary of the fall of Saigon. They had been warned to expect anti-American sentiment. "The State Department reports painted a very hazardous and unfriendly picture," wrote Greene in a travelogue of the trip. "How dangerous is it going to be this time?" he recalls remembering. "Can we expect hostility or worse?"

"Yankee Air Pirates"

The return to old Saigon quickly put them at ease. On the way from the airport to their hotel, they noticed that the buses no longer had anti-hand grenade screens on the windows, as was the case in the war years. "The people were very friendly, happy, and smiling," wrote Greene. "They treated us with open friendliness, even when it was revealed that we were 'Yankee Air Pirates.' "

The Mistys flew the next day to Hue, about 60 miles south of the old DMZ. There they met their guide, who during the war had been a combat interpreter for the US Marines. Then they began exploring in earnest. At first, they wanted to drive to Khe Sanh, where Mistys had made extensive flights during the North Vietnamese siege of 1968. The guide talked them out of it, explaining that the old fire base was completely overgrown, marked only by a simple monument to the North Vietnamese troops who died storming the base.

So the Mistys set out for other landmarks, some meaningful only to them. Near the old Con Thien Marine outpost, just across the river from what had been North Vietnam, they stopped and inspected the one remaining bunker. The outpost is totemic to the Mistys. Bud Day, the first Misty commander, had been shot down 25 miles north of Con Thien in 1967. He was captured by Communist forces but escaped after four days. Barefoot and badly injured, he trudged south for two weeks until he was within two miles of Con Thien and safety. Then, while trying to attract the attention of a US airplane overhead, he was shot by two North Vietnamese soldiers, recaptured, and sent to a Hanoi prison for nearly six years. For his gallantry, Day was awarded the Medal of Honor.

The pilots shot pictures of the bridge near the village of Cam Lo, near the DMZ, where North Vietnamese tanks streamed into the south in 1972. US commanders wanted to destroy the bridge but couldn't because a downed pilot was hiding nearby. Then, just before crossing the Ben Hai River, which had formed the center of the DMZ and marked the boundary between North and South Vietnam, the Mistys stopped at the Cemetery of the Martyrs of the Ho Chi Minh Trail.

"For me, it was the most emotional moment of the trip," said Don Shepperd, Misty 34 (and, in the period 1994-98, director of the Air National Guard). "The entire magnitude of the war hits you when you're walking around there. ... We've got the Wall here. They've got the cemeteries there. And what did we accomplish?"

The Mistys crossed the Ben Hai River and were on the territory of the old North Vietnam. The rice fields stretching to the horizon were dotted with bomb craters, filled with water and put to use growing shrimp and other fish. At nightfall they arrived at Dong Hoi, which had been leveled by US bombs but is now totally rebuilt and shows no obvious scars from the war. After a few go-arounds with the hotel staff, the Mistys managed to get a bucket of cold Heinekens and settled in to prepare for the next day's journey-the trip to the Disappearing River.

Panda, Sandy, and Jolly

At the cave, they photographed the bomb-scarred cliff that soars above it, where one of the most dramatic rescues of the war took place. Panda 01, an F-105 pilot, had gone down smack on top of the cave. Fighters, controlled by the Mistys, worked for two days to silence at least 18 AAA guns defending the area. At one point, Robinson's jet got so low on fuel that he probably would have flamed out had not a KC-135 tanker flown 20 miles beyond its permitted flight path-into North Vietnamese airspace-to help out. Finally, as one of the Jolly Green rescue helicopters was hovering in place and a pararescueman climbed down a rope ladder to snatch up the pilot, fire erupted from an unnoticed gun site. An A-1 Sandy rescue airplane rolled in and performed what Robinson described as a "heroic, selfless move." The Sandy made himself, rather than the Jolly Green, the target. As the Sandy dove toward the gun position, tracers started firing at him instead of the chopper. The Sandy continued flying straight into the gunner's fire, strafing and dropping cluster bombs. He pulled off just feet above the gun. The Sandy won the kill-or-be-killed showdown, enabling the Jolly Green to hoist the pilot to safety. The rescue, said Robinson, "evokes strong memories every time I tell the tale."

Spirits were high after the visit to the cave, and they soon rose higher. The Mistys hired a sampan to take them back down the river in search of the spot where a notorious six-position 57 mm AAA site routinely harassed them. They found no signs of the gun site, but there were plenty of craters caused by bombs that had been dropped to take it out. They also photographed another mountaintop where an F-105 pilot had crashed. Rutan had seen his parachute and flown to a tanker to fuel up for a rescue effort, but when he returned, there was no sign of the pilot. Most likely, the North Vietnamese found and killed him.

The trip down the river also brought the Mistys into a number of villages where they were not sure whether they would be greeted with warmth or anger. Their anxiety rapidly dissolved, however, as they were mobbed by poor but polite kids. Risinger delighted the children with a disappearing handkerchief trick, and the Mistys passed out candy, pencils, and other small gifts that they had brought along. Some of the kids practiced the halting English they had learned in school. The Mistys in general found the Vietnamese friendliness to be a surprise. "If I lived there and you'd been bombing me daily, I'd be [angry]," said Shepperd, "but they're not. I don't understand it."

Sign Language

One evening in Dong Hoi, Risinger decided to go for an after-dinner stroll, and he ran into Rutan doing the same thing. Although the town was poorly lit, they felt comfortable enough to walk far from their hotel. Eventually, they came across a shop near the seafront, filled with locals watching a single, ancient television set. They waded into the crowd, began chatting with gestures and simple words, and eventually explained they had been enemy pilots flying over Dong Hoi during the war. Some of the townsmen put their fingers in the air and went, "Duh-duh-duh-duh-duh"-indicating they had been air defense gunners. There was no animosity between the former foes. "The people were incredibly friendly," said Risinger.

For some Mistys, wartime frustration at the doggedness of the enemy turned into admiration. "They are courageous, inventive people," said Shepperd. "I have respect for them as soldiers and as people for what they underwent." The impression was reinforced a couple of days after the visit to the Disappearing River, when the group toured the Vinh Moc tunnels just north of the old DMZ. For years, the tunnels housed more than 3,000 locals, even though the passageways were so narrow people could only turn around at junctions where two tunnels intersected. The Mistys had to stoop to walk through most of the tunnels. Robinson, the former POW, could not even bring himself to descend into the complex. "I got about one foot in and decided I didn't want to do this," he said.

The trip caused some of the FACs to consider the possible ways they would help their former enemies. Wells Jackson, Misty 50, said he wished he could use 30 years' worth of accumulated entrepreneurial skill to aid the locals. "I have always respected the Vietnamese people as friendly, attractive, and hardworking," said Jackson. However, corruption and Communist restraints, he believes, make economic progress unlikely. "This greatly saddens me," he said. Still, not all of the Mistys are so enamored with the Vietnamese. One former pilot Rutan invited on the trip said he was still so mad at Vietnam that he'd do "terrible things" if he were to travel there.

The day after trekking to the Disappearing River, the Mistys set out for the Mu Gia Pass, tucked even farther into the Vietnam backcountry. The principal objective was to find the site of the gun that shot down Rutan's aircraft. Along the way, the Mistys conducted an old fighter pilot ritual. On an indistinct hilltop, where they figured no American had ever stood, they steered off the road and found a clump of grass. They pulled out a nickel given to them by Mary Fiorelli, wife of the late Jim Fiorelli, Misty 31, who died in 1994. Tossing it onto the grass, they sang:

Hallelujah! Hallelujah!
Throw a nickel on the grass,
Save a fighter pilot's ass.
Hallelujah! Hallelujah!
Throw a nickel on the grass,
And you'll be saved.

The ceremony took perhaps 30 seconds, but it was a time of introspection. "We had a silent moment," said Rutan. "I was thinking of all the guys who died up here."

They returned to the van. As they neared the Mu Gia Pass, where the Ho Chi Minh Trail crossed into Laos, the road became narrower and then, finally, impassable. Rutan persuaded the group to continue on foot. A couple of miles up ahead, a sign informed them that, during the latter years of the war, the road had been converted into an airstrip for North Vietnamese MiGs. They paced off the length of the strip and found it measured about 8,000 feet-too short for comfortable operations by US fighters of that era. They never made it to the Mu Gia Pass, although Rutan announced a plan to return someday and backpack from the airfield to the pass, then into Laos, and then back across the Vietnam border to Khe Sanh-a 100-mile excursion. He got no takers.

The next day the Mistys began the drive back to Hue, where they spent the night before flying back to Saigon. On stops at villages along the way, they were repeatedly mobbed by kids. In one town, they were invited to join in a wedding celebration, "totally disrupting the reception," according to Greene. In Hue, they visited the "American War Museum," which, like the one they later toured in Saigon, is replete with anti-American propaganda. One picture showed 11 girls who supposedly wiped out a US combat battalion. Also on display are some of the 37 and 57 mm guns that regularly shot at the Mistys, along with the reinforced bicycles couriers used to transport as much as 1,000 pounds of materiel down the North Vietnamese supply lines.