Finally, Giordino set aside the computer and called Pitt. "Dirk?"

    "I hear you."

    "Bad news. There isn't enough air left in your tanks for the lady and her friend to make the necessary decompression stops."

    "Tell me something I don't know," Pitt came back. "What about backup tanks in the chopper?"

    "No such luck," moaned Giordino. "In our rush to leave the ship the crew threw on an air compressor but forgot to load extra air tanks."

    Pitt stared through his face mask at Rodgers, still clutching his camera and shooting pictures. The photographer gave him a thumbs up sign as though he'd just cleared the pool table at the neighborhood saloon. Pitt's gaze moved to Shannon. Her hazel eyes stared back at him through her face mask, wide and content as if she thought the nightmare was over and her hero was going to sweep her off to his castle. She had not realized the worst was far from over. For the first time he noticed that she had blond hair, and Pitt found himself wondering what she looked like in only her swim suit without the diving equipment.

    The daydream was over almost as soon as it was begun. His mind came back on an even keel and he spoke into his face mask receiver. "Al, you said the compressor is on board the chopper."

    "I did."

    "Send down the tool kit. You'll find it in the storage locker of the chopper."

    "Make sense," Giordino urged.

    "The manifold valves on my air tanks," Pitt explained hastily. "They're the new prototypes NUMA is testing. I can shut off one independently of the other and then remove it from the manifold without expelling air from the opposite tank."

    "I read you, pal," said an enlightened Giordino. "You disconnect one of your twin tanks and breathe off the other. I pull up the empty and refill it with the compressor. Then we repeat the process until we satisfy the decompression schedule."

    "A glittering concept, don't you think?" asked Pitt with dark sarcasm.

    "Fundamental at best," grunted Giordino, artfully concealing his elation. "Hang at six-point-five meters for seventeen minutes. I'll send the tool kit down to you on the safety line. I just hope your plan works."

    "Never a doubt." Pitt's confidence seemed genuine. "When I step onto firm ground again, I'll expect a Dixieland band playing `Waiting for the Robert E. Lee'."

    "Spare me," Giordino groaned.

    As he ran toward the helicopter, he was confronted by Miller.

    "Why did you stop?" the anthropologist demanded. "Good God, man, what are you waiting for? Pull them up!"

    Giordino fixed the anthropologist with an icy stare. "Pull them to the surface now and they die."

    Miller looked blank. "Die?"

    "The bends, Doc, ever hear of it?"

    A look of understanding crossed Miller's face, and he slowly nodded. "I'm sorry. Please forgive an excitable old bone monger. I won't trouble you again."

    Giordino smiled sympathetically. He continued to the helicopter and climbed inside, never suspecting that Miller's words were as prophetic as a lead dime.

    The tool kit, consisting of several metric wrenches, a pair of pliers, two screwdrivers, and a geologist's hammer with a small pick on one end, was tied loosely to the safety line by a bowline knot and lowered by a small cord. Once the tools were in Pitt's hands he gripped the air tank pack between his knees. Next he adroitly shut off one valve and unthreaded it from the manifold with a wrench. When one air tank came free, he attached it to the cord.

    "Cargo up," Pitt announced.

    In less than four minutes, the tank was raised by willing hands on the secondary cord, connected to the throbbing gas-engine compressor and taking on purified air. Giordino was cursing, sweet talking, and begging the compressor to pump 3500 pounds of air per square inch into the 100-cubic-foot steel tank in record time. The needle on the pressure gauge was just shy of 1800 pounds when Pitt warned him that Shannon's pony bottle was dry and his lone tank had only 400 pounds left. With three of them sucking on one tank, that did not leave a comfortable safety margin. Giordino cut off the compressor when the pressure reached 2500 and wasted no time in sending the tank back down into the sinkhole. The process was repeated three more times after Pitt and the other divers moved to their next decompression stop at three meters, which meant they had to endure several minutes in the slime. The whole procedure went off without a hitch.

    Giordino allowed an ample safety margin. He let nearly forty minutes pass before he pronounced it safe for Shannon and Rodgers to surface and be lifted to the brink of the sacrificial pool. It was a measure of his complete confidence in his friend that Pitt didn't even bother to question the accuracy of Giordino's calculations. Ladies went first as Pitt encircled Shannon's waist with the strap and buckle that was attached to the safety and communications line. He waved to the faces peering over the edge and Shannon was on her way to dry land.

    Rodgers was next. His utter exhaustion after his narrow brush with death was forgotten at the sheer exhilaration of being lifted out of the godforsaken pool of death and slime, never, he swore, to return. A gnawing hunger and a great thirst mushroomed inside him. He remembered a bottle of vodka that he kept in his tent and he began to think of reaching for it as though it were the holy grail. He was high enough now to see the faces of Dr. Miller and the Peruvian archaeology students. He had never been as happy to see anyone in his life. He was too overjoyed to notice that none of them was smiling.

    Then, as he was hoisted over the edge of the sinkhole, he saw to his astonishment and horror a sight that was completely unexpected.

    Dr. Miller, Shannon, and the Peruvian university students stepped back once Rodgers was on solid ground. As soon as he had unbuckled the safety line he saw that they all stood somberly with their hands clasped behind their necks.

    There were six in all, Chinese-manufactured Type 56-1 assault rifles gripped ominously by six pairs of steady hands. The six men were strung out in a rough semicircle around the archaeologists, small, blank-faced, silent men dressed in wool ponchos, sandals, and felt hats. Their furtive dark eyes darted from the captured group to Rodgers.

    To Shannon, these men were not simple hill-folk bandits supplementing their meager incomes by robbing visitors of food and material goods that could be hawked in public markets, they had to be hardened killers of the Sendero Luminoso ("Shining Path"), a Maoist revolutionary group that had terrorized Peru since 1981 by murdering thousands of innocent victims, including political leaders, policemen, and army soldiers. She was suddenly gripped by terror. The Shining Path killers were notorious for attaching explosives to their victims and blasting them to pieces.

    After their founder and leader, Abimael Guzman, was captured in September 1992, the guerrilla movement had split into unorganized splinter groups that carried out haphazard car bombings and assassinations by bloodcrazed death squads that achieved nothing for the people of Peru but tragedy and grief. The guerrillas stood around their captives, alert and watchful, with sadistic anticipation in their eyes.

    One of them, an older man with an immense sweeping moustache, motioned for Rodgers to join the other captives. "Are there more people down there?" he asked in English with the barest trace of a Spanish accent.