Pitt immediately recognized the opening as a lava tube. Its cylindrical-shaped walls were almost perfectly formed, rounded and smoothed as if made by a machine. But the passage was actually the result of a steady flow of hot lava cooling on the surface and creating an outer crust. The liquid center ultimately flowed out, leaving a hollow tube. Lava tubes have been found that stretch fifty feet wide, while a few run several miles long. Summer's tube was relatively small, stretching about six feet in diameter.
Pitt followed the tube for thirty feet, noticing a gradual ascent on his depth gauge. The tube suddenly flared wide, and he noticed a reflection from his flashlight just before his head broke the surface of a calm pool of water. Bobbing on the surface, he turned the light around him. Steep black walls of lava fell vertically to the water on three sides. The fourth side, however, opened to a wide, rocky clearing. Pitt kicked lazily toward the landing as the underwater lights of Summer and Dirk surfaced near him. They all swam to the rocks and climbed out of the water before anyone spat out their regulators and spoke.
"It's amazing," Summer said. "An underground cavern fed from a flooded lava tube. Though it could use a little air-conditioning." The air in the cave was dank and musty, and Summer contemplated keeping her tank and regulator on.
"It was likely a much deeper cave at one time, but became sealed off by the lava flows gushing down the mountainside," Pitt said. "It's a fluke that a lava tube happened to form at its entrance."
Dirk dropped his tank and weight belt, then flashed his light around the clearing. Something caught his eye in the rocks.
"Summer, behind you."
She turned and gasped at the sight of a man standing just a few feet away. She stifled a cry at realizing that the man wasn't real.
"A clay warrior?" Dirk asked.
Summer shined her light and noticed another figure standing nearby. They were both life-sized figures, with painted uniforms and sculpted swords. Summer crept closer, eyeing the artisans' detail. They were soldiers, and each had braided hair, and a stringy mustache beneath almond-shaped eyes.
"Emperor Qin's terra-cotta warriors of Xian?" Pitt said. "Or perhaps a thirteenth-century facsimile."
Summer looked at her father quizzically. "Thirteenth century? What are they doing here?"
Pitt stepped up to the two figures and noticed a small path that ran between them, cut through the lava.
"I think they are guiding us to the answer," he said. Stepping between the clay sculptures, he followed the path, with Dirk and Summer in tow. The worn trail twisted around several walls of lava, then suddenly opened into a wide, cavernous room.
Pitt stood at the threshold with his two children, shining their flashlights in awe. The huge chamber was filled with an army of clay figures flanking the walls. Each wore a heavy necklace of gold or an amulet studded with gemstones. Positioned inside the clay warriors was another ring of sculptures, mostly scale figures of animals. Some were carved jade or stone, while others were gilded with gold. Deer grazed fearlessly next to large falcons. A pair of prancing white mares was showcased near the center of the room.
Interspersed with the sculptures were dozens of small lacquered cabinets and tables covered in dust. On a large teak table, Summer noticed an elaborate place setting that shone under her light. The plates, flatware, and goblets sitting atop a silk mat were all cast in gold. Adjacent to the table was an assortment of silver and gold ornaments, some adorned with Arabic lettering and literary Chinese script. Other tables held mirrors, boxes, and art objects glistening with decorative gemstones. Summer crept to a nearby cabinet covered with scenes of battle painted in bright colors and pulled open a drawer. Inside, trays of amber, sapphires, and rubies filled the silk-lined case.
The sculptures and jewels didn't interest Pitt. He stared past the artifacts toward the centerpiece of the entire chamber. On a raised stone platform in the middle of the room stood a long wooden box. It was painted bright yellow and featured detailed carvings on each panel. Pitt stepped closer and shined his light at the top of the box. A stuffed cheetah, its teeth bared and a clawed paw scratching the air, seemed to hiss back at Pitt. He lowered his light to the top surface of the box and smiled at the image. A large wolf, painted blue, was emblazoned across the surface.
"May I present the late emperor of the Yuan Empire, Kublai Khan," he said.
"Kublai Khan," Summer whispered in reverence, her eyes wide. "It can't be."
"I thought he was buried somewhere near Genghis," Dirk said.
"According to popular legend. But the tale just didn't seem to add up. Borjin was able to locate the grave of Genghis Khan with his seismic device, but he never found Kublai. They should have been buried in the same ballpark. Then your Dr. Tong appears here, sidestepping a mission to disrupt the Alaska Pipeline in order to visit a shipwreck? There was obviously a greater draw, something only the Borjins could appreciate. I suspect they may have found an empty tomb for Kublai in Mongolia, or discovered some other clue that he was buried elsewhere."
"I still don't see how that leads here," Summer said.
"The story is in the cheetah skin. It was discovered at Shang-tu, so it had an original link with Kublai.
The emperor was known to possess trained cheetahs used for hunting, so the skin may have even come from one of his pets. More relevant was that the cheetah skin was unearthed together with a silk map that purportedly showed the location of Genghis Khan's tomb. Borjin's father acquired the silk map, and Borjin himself admitted that it helped lead to the grave site. For some reason, the significance of the cheetah skin paintings was overlooked when first found. The blue wolf was the trigger for me."
"What blue wolf?" Summer asked.
"A design motif," he said, pointing to the image painted on the elevated wooden coffin. "It was a known emblem for the imperial khans, originated by Genghis. If you look at the cheetah skin closely, you can see a banner of a blue wolf flying on the mast of the burning junk in the last painting. It wouldn't be flown except in the presence of a khan. Your wreck, which matched the depiction of a royal vessel departing China on the panels, was dated fifty years after the death of Genghis. Too late for him to be taking a cruise. No, the dates align with the era when Kublai ruled. And died. The secret of the cheetah skin is that it shows the final voyage of Kublai Khan."
"But why was he brought to Hawaii?" Summer asked, passing her light across the length of the sarcophagus. She held the beam momentarily on a twisted wooden staff that leaned against one end of the tomb. She noted curiously that a shark-tooth necklace dangled from its worn grip.
"His last years were difficult ones. Perhaps his 'voyage to paradise' was a plan to spend eternity on a faraway shore."
"Dad, how did you know his tomb survived the volcanic blast and that we could find it?" Dirk asked.
"Whoever painted the cheetah skin had seen the tomb and treasures and had known they survived the lava flows, otherwise they would have been depicted in flames as well. I took a gamble on the entrance.
The sea levels are higher than they were eight hundred years ago, so I figured the entrance might now be underwater."
"The treasures here must represent the riches accumulated during his lifetime of conquest," Dirk said, stunned at the sheer volume around him. "Perhaps some of the items were amassed during the reign of Genghis as well. It must be worth an untold fortune."
"The Mongolian people were cheated out of Genghis Khan's treasure. It would only be fitting if they secure the riches of Kublai Khan. I trust they will find a more appropriate burial spot, on Burkhan Khaldun, where Kublai can spend eternity."