Emily Davis Mobley was exactly where she wanted to be—a thousand feet below the surface of the earth, the lamp on her helmet piercing the total darkness. The tunnels and chambers of Lechuguilla Cave, in New Mexico's Carlsbad Caverns National Park, 55 miles long and plumbed to a depth of 1,565 feet so far, are as treacherous as they are wondrous. There are sheer cliffs up to 250 feet high and yawning 150-foot pits. Passageways so narrow that cavers must wriggle through on their bellies to rooms festooned with spectacular mineral formations: gypsum and limestone that can resemble chandeliers, candelabras and pillars. Some of the structures are so fragile that they could crumble into dust from the vibrations of a nearby footfall, a threat that has prompted the National Park Service to tightly restrict access to Lechuguilla to only the most experienced cavers. [P] The eerie beauty of Lechuguilla is what brought Mobley, 40, and 55 fellow enthusiasts to the nation's deepest cave on March 30. Their aim was to map sections of the cave, which was discovered only in 1986. For Emily it was a busman's holiday. Back in rural Schoharie, N. Y., she sells caving equipment by mail from the farmhouse she shares with her husband. Bill, 46, a rare-books dealer. Known to cavers all over the country, Emily readily admits, "My life pretty much revolves around caving." [P] And so could have her death. Early in the second morning of their outing, an 80-pound boulder knocked Emily down and smashed her left leg. Her rescue would have been considerably more arduous had it not been for her team's meticulous planning and the skill, nerve and selflessness of the spelunking community. During the next four days, while her husband waited at home, cavers from as far off as New York plunged into Lechuguilla and in a superbly orchestrated rescue brought her on a tortuous route back to the surface. Correspondent Michael Haederle spoke to Mobley and the leaders of her rescue about the ordeal. [P] Mobley: We woke up about 1:30 A.M. on Sunday and hiked to a western section of the cave to explore an unsurveyed and unnamed pit that opened below. I climbed unroped into the pit down a long, steep slope. I held one end of a tape measure while one of the members of my team read out a measurement and pulled the tape back up. I started climbing, and when I was near the top, I grabbed a rock to my left. It didn't just shift; it sort of jumped at me. The rock pushed me down the slope about 10 feet, and I lunged to my right to get out of the way. It scraped by my arm and landed on my leg. When it hit. I heard a crunch—a snap. [P] Dr. Steve Mosberg, 37, a general practitioner from Vienna, W.Va., who rushed to Mohley's aid after hearing her fall and remained with her throughout the rescue: I checked to see if there were any life-threatening injuries. There weren't, so I called for a space blanket [a sheet of aluminized plastic which I folded into a pad and secured alongside her knee with Ace bandages to make a primitive splint. [P] Mobley: After that it took about 20 minutes to get me out of the pit and onto a fiat piece of rock. I was mostly thinking, "Oh, my God, I've ruined the expedition." I've been caving for 22 years. I wasn't the least bit worried about getting out of the cave. I was attempting to keep the pragmatic part of me in the forefront and the emotional side of me under control. I worked very hard at that, because I knew it would make the rescue easier for everyone. [P] Another member of Mobley's team immediately set off for a campsite on the way to the mouth of the cave to summon help. Within hours the Park Service was gearing up its rescue effort. [P] Mosberg: The main problem with a broken leg is swelling and pain. As it turned out, another survey team came by, and one of the members was carrying some Percocet, a fairly strong oral narcotic that he was taking for the aftereffects of abdominal surgery. Using that, we were able to relieve her pain and make her comfortable. But we didn't want to knock her out, because we needed her to be conscious when the rescue started. [P] The other main thing you worry about with a broken leg is the phenomenon known as fat emboli. Fat droplets from the bone marrow can get into the bloodstream and cause damage in the lungs and brain. It's the sort of thing you can watch for, but there isn't a heck of a lot you can do if it happens in a cave. [P] Jim Goodbar, a search and rescue expert with the Bureau of Land Management in Carlsbad who entered the cave Monday morning to help direct the scores of cavers beginning the task of getting Mobley out: This is back-breaking work. We had to take her litter through narrow, low-ceilinged passages. At some points we had to get down on our hands and knees, rest the litter on our backs and shoulders and pass it overhead hand to hand. It's called turtling. Progress can be slow at times; we'd move the litter five feet and then have to stop for a rest. [P] The rescuers worked as much as 16 hours a day in the 70°F, 95 percent humidity of the cave, rotating every few hours for relief. They ate a high-calorie mix of nuts and raisins and military-style prepackaged meals supplied by the Park Service; Mobley preferred to munch on Granny Smith apples and crackers. [P] Mobley: The time I felt most distraught was when my litter was hanging vertically, because my weight was on the broken bone and the pain was worse. I tend to be a bit hyperactive and being strapped in a totally unmoving position would have been extremely uncomfortable. So the rescuers left my hands and shoulders free. Still I felt I had no physical control over what was happening. Another problem was nausea from the up-and-down movement of being carried over large boulders. There were a few times when I got motion sickness. [P] Rick Bridges, a leader of the rescue effort who talked to Mobley via radio-telephone relay on the third day of the rescue: She said she thought she had the hottest rescue team on the surface of the earth. I said that isn't quite correct: She had the hottest rescue team under the earth. [P] Mobley: At one point I was lying there, and I looked up and saw this friend of mine from California, and I said, "Joe, what are you doing here?" He said. "I flew in to help with the rescue. I heard you were in the cave and they needed stretcher-bearers." [P] Early 'Thursday morning, 96 hours into the rescue, as Mobley approached the mouth of the cave, she entertained her rescuers with tuneful lyrics like "Jeremiah was a bullfrog" and "Are the stars out tonight ?" [P] Mobley: I was just exhausted, but it was really pretty to see the stars. They wheeled me a mile and a half to where an ambulance was waiting to take me to Guadalupe Medical Center in Carlsbad. The doctors put a bolt with two nuts through the area above my shin. There's some question whether I will ever be totally normal again. But if I work at it, I should be able to regain the full use of my leg. I hope to be caving again this summer. There's no way this is going to slow me down. [P]