Gratefully, Pitt let go of the line and sagged to a sitting position to catch his breath. "They can ascend on their own from there."

    Giordino was the first of the two divers to surface. He removed his twin air tanks and hoisted them to Sandecker. Then he offered a hand to Pitt who leaned back and heaved him out of the water. The next man up was Dr. Peter Duncan, a U.S. Geological Survey hydrologist, who had arrived in Calexico by chartered jet only an hour after Sandecker contacted him in San Diego. At first he thought the admiral was joking about an underground river, but curiosity overcame his skepticism and he dropped everything to join in the exploratory dive. He spit out the mouthpiece to his air regulator.

    "I never envisioned a water source that extensive," he said between deep breaths.

    "You found an access to the river," Pitt stated., not asked, happily.

    "The sinkhole drops about sixty meters before it meets a horizontal feeding stream that runs a hundred and twenty meters through a series of narrow fissures to the river," explained Giordino.

    Can we gain passage for the float equipment?" Pitt queried.

    "It gets a little tight in places, but I think we can squeeze it through."

    "The water temperature?"

    "A cool but bearable twenty degrees Celsius, about sixty-eight degrees Fahrenheit."

    Duncan pulled off his hood, revealing the great bush of a red beard. He made no effort to climb from the pool. He rested his arms on the bank and babbled in excitement. "I didn't believe it when you described a wide river with a current of nine knots under the Sonoran Desert. Now that I've seen it with my own eyes, I still don't believe it. I'd guess anywhere from ten to fifteen million acre-feet of water a year is flowing down there."

    "Do you think it's the same underground stream that flows under Cerro el Capirote?" asked Sandecker.

    "No doubt about it," answered Duncan. "Now that I've seen the river exists with my own eyes, I'd be willing to gamble it's the same stream that Leigh Hunt claimed runs beneath the Castle Dome Mountains."

    "So Hunt's canyon of gold probably exists." Pitt smiled.

    "You know about that legend?"

    "No legend now."

    A delighted look crossed Duncan's face. "No, I guess not, I'm happy to say."

    "Good thing we were tied to a fixed guideline," said Giordino.

    Duncan nodded. "I couldn't agree more. Without it, we would have been swept away by the river when we emerged from the feeder stream."

    "And joined those two divers who ended up in the Gulf."

    I can't help but wonder where the source is," mused Sandecker.

    Giordino rubbed a hand through his curly mop. "The latest in geophysical ground-penetrating instruments should have no problem tracking the course."

    "There is no predicting what a discovery of this magnitude means to the drought-plagued Southwest," said Duncan, still aroused by what he'd seen. "The benefits could result in thousands of jobs, millions of acres brought under cultivation, pasture for livestock. We might even see the desert turned into a Garden of Eden."

    "The thieves will drown in the water that makes the desert into a garden," Pitt said, staring into the crystal blue pool and remembering Billy Yuma's words.

    "What was that you said?" asked Giordino curiously.

    Pitt shook his head and smiled. "An old Indian proverb."

    After carrying the dive equipment up to the surface entrance of the borehole, Giordino and Duncan stripped off their suits while Sandecker loaded their gear into the Plymouth station wagon. The admiral came over as Pitt drove alongside in the old pickup and stopped.

    "I'll meet you back here in two hours," he notified Sandecker.

    "Mind telling us where you're going?"

    "I have to see a man about raising an army."

    "Anybody I know?"

    "No, but if things go half as well as I hope, you'll be shaking his hand and pinning a medal on him by the time the sun goes down."

    Gaskill and Ragsdale were waiting at the small airport west of Calexico on the United States side of the border when the NUMA plane landed and taxied up to a large Customs Service van. They had begun transferring the underwater survival equipment to the van from the cargo hatch of the plane when Sandecker and Giordino arrived in the station wagon.

    The pilot came over and shook their hands. "We had to hustle to assemble your shopping list, but we managed to scrounge every piece of gear you requested."

    "Were our engineers able to lower the profile of the Hovercraft as Pitt requested?" asked Giordino.

    "A miraculous crash job." The pilot smiled. "But the admiral's mechanical whiz kids said to tell you they modified the Wallowing Windbag down to a maximum height of sixty-one centimeters."

    "I'll thank everyone personally when I return to Washington," said Sandecker warmly.

    "Would you like me to head back?" the pilot asked the admiral. "Or stand by here?"

    "Stick by your aircraft in case we need you."

    They had just finished loading the van and were closing the rear cargo doors when Curtis Starger came racing across the airstrip in a gray Customs vehicle. He braked to a stop and came from behind the wheel as if shot out of a cannon.

    "We got problems," he announced.

    "What kind of problems?" Gaskill demanded.

    "Mexican Border Police just closed down their side of the border to all U.S. traffic entering Mexico."

    "What about commercial traffic?"

    "That too. They also added insult to injury by putting up a flock of military helicopters with orders to force down all intruding aircraft and stop any vehicle that looks suspicious."

    Ragsdale looked at Sandecker. "They must be onto your fishing expedition."

    "I don't think so. No one saw us enter or leave the borehole."

    Starger laughed. "What do you want to bet that after Senor Matos ran back and reported our hard stand to the Zolars, they frothed at the mouth and coerced their buddies in the government to raise the drawbridge."

    "That would be my guess," agreed Ragsdale. "They were afraid we'd come charging in like the Light Brigade."

    Gaskill looked around. "Where's Pitt?"

    "He's safe on. the other side," replied Giordino.

    Sandecker struck the side of the aircraft with his fist. "To come this close," he muttered angrily. "A bust, a goddamned bust."

    There must be some way we can get these people and their gear back to Satan's Sink," said Ragsdale to his fellow federal agents.

    Starger and Gaskill matched crafty grins. "Oh, I think the Customs Service can save the day," said Starger.

    "You two got something up your sleeves?"

    "The Escobar affair," Starger revealed. "Familiar with it?"

    Ragsdale nodded. "The underground drug smuggling operation."

    Juan Escobar lived just across the border in Mexico," Starger explained to Sandecker and Giordino, "but operated a truck repair garage on this side. He smuggled in a number of large narcotics shipments before the Drug Enforcement Agency got wise to him. In a cooperative investigation our agents discovered a tunnel running a hundred and fifty meters from his house under the border fence to his repair shop. We were too late for an arrest. Escobar somehow got antsy, shut down his operation before we could nail him, and disappeared along with his family."