He floated on his back and examined the walls that seemed to reach to a passing cloud, and tried to recall what he'd read about limestone in what seemed a centuries-old geology course in college. Limestone: a sedimentary rock composed of calcium carbonate, a sort of blend of crystalline calcite and carbonate mud, produced by lime-secreting organisms from ancient coral reefs. Limestones vary in texture and color. Not bad, Pitt thought, for a student who pulled a B - in the course. His old teacher would be proud of him.
He was lucky he wasn't facing granite or basalt. The limestone was pockmarked with small hollow cavities and lined with tiny edges. He swam around the circular walls until he was under a small outcropping that protruded from the side about halfway to the top. He removed his air tank pack and the rest of his diving gear, except for the accessory belt, and let it drop to the floor of the sinkhole. All he kept were the pliers and the geologist's pick hammer from the tool kit. If for some unfathomable reason his best friend and the archaeologists above the ledge had been killed or wounded, and Pitt had been left to die in the sacrificial pool with only the ghosts of previous victims for company, he was damned well going to find out why.
First, he pulled a dive knife from a sheath strapped to his leg and cut off two lengths of safety line. He tied one section of the line tightly to the narrow section of the pick hammer's handle close to the head so it wouldn't slip over the wider base. Then he tied a step-in loop at the free end of the line.
Next he rigged a hook from the buckle of his accessory belt, bending it with the pliers until it resembled a C. He then fastened the second section of line to the hook with another step-in loop. When he was finished, he had functional, though rudimentary, climbing tools.
Now came the tough part.
Pitt's climbing technique was not exactly that of a veteran mountaineer. The sad truth was that he had never climbed any mountain except on a beaten trail by foot. What little he'd seen of experts scaling vertical rock walls came from public service television or magazine articles. Water was his element. His only contact with mountains was an occasional ski trip to Breckenridge, Colorado. He didn't know a piton (a metal spike with a ring in one end) from a carabiner (an oblong metal ring with a springloaded closing latch that hooks the climbing rope to the piton). He vaguely knew rappelling had something to do with descending a rope that wrapped under a thigh, across the body, and over the opposite shoulder.
There wasn't an expert climber in the business who would have given five hundred to one odds Pitt could make it to the top. The problem with the odds was that Pitt was too stubborn to even consider them. The old diehard Pitt came back on balance. His mind felt clear and sharp as a needle. He knew his life, and perhaps the lives of the others, hung on an unraveling thread. Cold, self-possessed inner resolve took hold as it had so many times in the past.
With a commitment bred of desperation, he reached up and stuck the belt hook into a small protruding edge of limestone. He then stepped into the loop, grasped the upper end of the line and pulled himself out of the water.
Now he lifted the hammer as high as he could reach, slightly off to one side, and rapped the pick end of the hammer into a limestone pocket. Then he placed his free foot in the loop and pulled himself to a higher stance up the limestone wall.
Crude by professional standards, Pitt mused, but it worked. He repeated the process, first with the C hook, then with the pick hammer, moving up the steep wall with his arms and legs articulating like a spider. It was exhausting effort even for a man in good physical condition. The sun had vanished below the tops of the trees as if jerked to the west by a string when Pitt finally climbed onto the small outcropping halfway up the steep wall. Still no sign from anyone above.
He clung there, thankful for the resting place, even though it was barely large enough to sit one of his buttocks on. Breathing heavily, he rested until his aching muscles stopped protesting. He could not believe the climb had taken so much out of him. An expert who knew all the tricks, he presumed, wouldn't even be breathing hard. He sat there hugging the sheer side of the sinkhole wall for almost ten minutes. He felt like sitting there for another hour, but time was passing. The surrounding jungle was quickly turning dark once the sun was gone.
Pitt studied the crude climbing tool that had taken him this far. The hammer was as good as new, but the C hook was beginning to straighten from the constant strain of supporting the dead weight of a human body. He took a minute to recurl the hook by beating it against the limestone with his pick hammer.
He had expected the darkness to shroud his vision, forcing him to scale the limestone by feel only. But a strange light was forming below him. He turned and stared down into the water.
The pool was emitting an eerie phosphorescent green light. No chemist, Pitt could only assume the strange emission was caused by some sort of chemical reaction from the decaying slime. Thankful for the illumination, however dim, he continued his grueling climb upward.
The last 3 meters (10 feet) were the worst. So near, yet so far. The brink of the sinkhole seemed close enough to touch with his outstretched fingertips. Three meters, no more. Just ten feet. It might as well have been the summit of Mount Everest. A high school track star could have done it in his sleep. But not Pitt. A few months on the low side of forty, he felt like a tired old man.
His body was hard and lean, he watched his diet and exercised just enough to maintain a steady weight. There were the scars from numerous injuries, including gunshot wounds, but all the joints still functioned in a reasonably satisfactory manner. He'd given up smoking years ago, but still indulged himself occasionally with a glass of good wine or a tequila on the rocks with lime. His tastes had changed through the years from Cutty Sark scotch to Bombay gin to Sauza Commemorativo tequila. If asked why, he had no answer. He met each day as if life-was-a-game and games-were-life, and the reasons for doing certain things were hermetically sealed and buried inside his head.
Then, when he was within reach of the sinkhole's edge, he dropped the loop attached to the C hook. One moment stiffening fingers were tugging it from the limestone, the next it was falling toward the water where it entered the weirdly glowing algae layer with hardly a splash to mark its entry. In combination with the pick hammer, he began using the pockets of limestone as toe- and handholds. Near the top he swung the hammer in a circle above his head and hurled it over the edge of the sinkhole in an attempt to implant the pick end into soft soil.
It took four tries before the sharp point dug in and remained firm. With the final reserve of his strength, he took the line in both hands and pulled his body up until he could see flat ground before him in the growing darkness. He lay quiet and studied his surroundings. The dank rain forest seemed to close in around him. It was dark now and the only light came from the few stars and a crescent moon that breached the scattered clouds and the intertwined branches of the crowded trees. The dim light that filtered down illuminated the ancient ruins with a ghostly quality that was equaled by the sinister, claustrophobic effect of the invading walls of the forest. The eerie scene was enhanced by the almost complete silence. Pitt half expected to see weird stirring and hear ominous rustling in the darkness, but he saw no lights or moving shadows nor heard voices. The only sound came from the faint splatter of a sudden light rain on the leaves.