HICKAM AIR FORCE BASE, Hawaii — Last month, yet another flag-draped metal box was ceremoniously borne through the back doors of the Central Identification Laboratory by four solemn soldiers.
Since then, scientists have given the new arrival their customary attention -- a kind of intense scrutiny seldom given to the living.
They have weighed and measured and X-rayed the mummified remains of the man who was found Oct. 16 in a glacier in the Sierra Nevada.
If he was one of four young airmen whose World War II training plane crashed nearby, he would have been encased in ice for nearly 63 years.
At the lab, near Pearl Harbor, investigators have combed through every fiber of his tattered green pants, green underwear and green cable-knit sweater, looking for a name, for laundry marks, for sizes that would indicate height and weight.
They have puzzled over high-tech ways to make out a severely corroded metal name tag that was still pinned over his heart, figuring it might have belonged to one of the men on the ill-fated 1942 flight.
They have conferred with a rare-manuscript expert at the University of Hawaii, who plans to freeze-dry the man's tiny red address book and tease open congealed pages that may be blank -- or may yield a wealth of clues to the man's identity.
"We go through thousands of items," said Robert Mann, deputy director of the lab, who is charged with identifying the remains of all American troops missing in action. "We take buttons and boots and grommets and lighters, and watches that stopped at the moment of impact. It all matters."
The well-preserved remains from California's Mt. Mendel are just another entry on the lab's long list of active cases.
The oldest is a soldier from the War of 1812. There also are two Civil War sailors found three years ago in the wreckage of the naval warship Monitor; one of them, scientists theorize, was a pipe smoker in his 40s who was accustomed to heavy labor.
They are brought here from around the world, sometimes bone by bone.
The pilot who couldn't make it over the Himalayas in World War II is flown from Tibet. The GI who disappeared in a blood-soaked German forest, the fighter jock who plunged into a Vietnamese rice paddy, the prisoners excavated from a mass grave in Korea -- America's lost who now are found wind up here.
Some are discovered by local residents tilling a field or clearing a forest. Others are found by teams from the lab and its parent agency, the Joint POW-MIA Accounting Command.
Each year, at least five expeditions are mounted to old battlegrounds and suspected crash sites, from Poland to Palau. Anthropologists, linguists and explosives experts travel to remote areas, interviewing locals and scouring the countryside for traces of missing American troops.
The fragments they find end up back at the lab.
In a large white room, scientists pore over 21 tables neatly arrayed with browning bones, patches of skull, shards of jaw -- all laid out head to toe, known only by the numbers they have been assigned.
When they are carried in, all are unknown soldiers. If they leave -- and some 1,100 unknowns are still shelved in boxes within the lab's vault -- they are returned to their families and, often, buried with full honors at Arlington National Cemetery.
Most other countries do not have similar operations, according to command officials. The agency operates on a budget of about $46 million annually. And about 100 service members are identified each year.
"It's a promise made to every person in uniform: We leave no comrades behind," said Maj. Rumi Nielson-Green, a spokeswoman for the lab. "I don't know why it's uniquely American. Maybe it's because we're a relatively new country and don't have many centuries of foreign battles behind us. But, to me, it makes absolute sense."
The U.S. effort has not always enjoyed either success or support. At a congressional hearing in 1986, top forensic anthropologists blasted the lab for slipshod methods, contending that there was no scientific basis for identifying 13 airmen missing in Laos from bone chips no bigger than a quarter.
Under pressure from families, the lab, accused of "voodoo forensics," was forced to rescind its conclusion in two of those cases.
The negative publicity helped spur a turnaround, said Tom Holland, the lab's current director. The staff was expanded, and anthropologists skilled in investigative work replaced a mortician and a handful of assistants. With 31 forensic anthropologists and three forensic dentists, the lab today claims to be the largest facility of its kind in the world.
As if to underscore the credentials of the staff, dozens of their scholarly papers have been posted on a bulletin board: "Last Meals: Recovering Abdominal Contents from Skeletonized Remains"; "Radiographic Examination of Chinese Foot binding"; "On Morning Sickness and the Neolithic Revolution."
Some of their most important research takes place out in the field, where the job gets harder with each passing year.