Sam grinned suddenly. “Maybe we can?”
Chapter Sixty-Three
Both men took a dozen or more deep breaths in and out. By hyperventilating they were reducing their carbon dioxide levels and turning their blood slightly alkaline. The benefit of which, was to offset the inevitable acidity that would be caused when they held their breaths for a prolonged period during the free-dive and reduce their urge to breath.
Sam caught Tom’s eye and nodded. It was time. He dipped his head under the water and back into the submerged tunnel. He quickly swam down the current until he reached the cave-in, approximately eighty feet ahead.
He glanced at the two small cracks in the limestone where water still flowed. One was shaped like the jagged opening to the mouth of a large fish or a small shark, while the other was larger and more rectangular. Sam placed his hand well above the opening and studied the shapes, mentally trying to picture a way to block their flow. He felt his arm pull toward the smaller of the two openings. The large channel of water flowing from the entire tunnel was being forced through the two small openings, causing an increase in speed and force of the current, much like a jet engine.
Sam moved away from the opening. Tom nodded and swam toward a pile of rocks lying on the base of the tunnel. Together they moved a series of smaller rocks until they were able to block the smaller of the two cracks. Instantly the strength of the current increased on the larger opening. They both then swam back to the opening in the ceiling where Zara waited.
Zara looked at them both. “What do you think, is it possible?”
Sam felt his chest burn as he breathed hard. He turned to Tom, as though to say, well, is it possible?
Tom looked at both of them with a non-committal smile. “It all depends.”
“On what?” she asked.
Tom said, “On whether or not we can find a suitable rock, large enough to block the remaining gap. Even then, it’s going to be a matter of time before the water punches another way through. If it made it once, it will do so again.”
It was nearly five minutes before they were ready to free-dive again. Repeating the same process of hyperventilation, Sam entered the water and returned to the cave-in. There were several large stones. Some would be impossible to move, while others were definitely too small. They chose the first one which looked approximately right. It was like a kite with a wide base and a narrow point.
Together Sam and Tom rolled the medium sized stone twenty feet until it was near the remaining crack in the limestone wall. Sam stood the stone up, so that it’s wider base was to the ground, and then carefully shimmied it on either end of its base until the stone stood directly in front of the opening. It was as much as they needed to do. The powerful current drew the stone in like a piece of flotsam reaching a storm drain.
It plugged the hole and the water stopped moving. Sam reached down to the ground and picked up a handful of small rocks and sand. He scattered the debris over the kite-shaped stone and was pleased to see none of the smaller stones were drawn into anything.
Sam watched for a moment and then returned to the opening where Zara waited for them.
Zara met his gaze and asked, “Did it work?”
In-between breaths, Sam said, “Looks like it.”
“Now what?” she asked.
Sam pulled off a small rock from the edge of the cave-in and marked it just above the waterline. “Now we wait and see if the water rises.”
Chapter Sixty-Four
It took a total of four hours for the water to rise high enough for them to be able to climb up onto the tunnel above the cave-in. Sam looked in both directions along the tunnel. Opposite the side he’d climbed, the tunnel appeared to have been completely damaged by the cave-in. That left only one direction to go, south.
They traveled quickly, intermittently alternating between a jog and a run. Sam felt good. The stories he’d heard about the ancient irrigation tunnels suggested some of them ran between cities and for hundreds of miles. This tunnel might very well travel all the way to Chad.
After about two hours, he stopped — because a second cave-in meant there was no way this tunnel was ever going to take them anywhere.
Zara swore loudly. “Tell me we can move this rubble!”
Sam ran his hands along the heavy boulders that barred their way. “It might be possible, but it’s going to take a long time, and a lot of luck.”
Tom was faster to reach the inevitable conclusion. “Neither of which we have right now. The water’s still flooding this area. If we turn around now, we might just be able to unblock the plug. But if we wait, we’ll never even reach the cave-in we entered here by. The water will start to flow down this tunnel like a flashflood, and there will be no way out.”
“All right,” Zara said. “I have no interest in drowning beneath the Sahara or anywhere else. Let’s return to the subterranean island, and then make a try crossing the desert into Chad.”
With all three in agreement, they raced back to the original cave-in. As they approached, water flowed to greet them. It was no more than five or six inches in height, but already it made it difficult to walk up the tunnel.
Tom, with his longer legs, pulled ahead of Sam and Zara. Sam lifted his legs as best he could as he ran, trying to keep up. It was the same technique used by Ironmen trying to reduce their drag, while racing through the surf. Despite his effort, Tom disappeared ahead of them.
Nearly thirty minutes later, Sam reached the cave-in through which they had entered the tunnel. It now looked like a lake instead of a gaping hole in the tunnel. Sam started to hyperventilate in preparation of the long free-dive. But before he dropped into the water, Tom surfaced.
Sam asked, “Did you reach it?”
“The plug’s gone, and the water’s draining freely again.” Tom looked around at the water still flowing down the tunnel. “It might take a while for all this water to dissipate, and longer still before we can swim back to the subterranean island.”
It took eight hours for the water to return to its normal height in the lower tunnel, where they were able to then swim against the current. It took a further four hours to reach the subterranean island. Sam pulled himself up onto the island, and then he and Tom lifted Zara out of the water. Every muscle in his body ached.
Zara said, “Well that’s it. We’ll have to wait as long as our food rations last, and then make an attempt at crossing the desert, into Chad.”
Sam shook his head. “I haven’t given up finding a way out of here, yet.”
“Really?” she asked. “You’re going to look for a third irrigation tunnel?”
“Why not?” Sam asked. “If there were two, there might as well be three. We only need one to lead to the surface a long distance away from here.”
“What do you want to do, Tom?” Zara asked. “Do you want to make another attempt to find a third tunnel out of here?”
Tom shrugged, as though he honestly hadn’t yet given the idea any thought. “Right now, I’m going to dry off and rest.”
She turned to Sam, again. “When will you make a second attempt?”
“Not for a while. I’ll need a day to rest and recuperate.”
She asked, “You want to go to sleep?”
“Not yet.” Sam took out his desert robes and used them to dry himself. “Tell me about Nostradamus. If that con artist worked out how to royally screw me from four hundred years ago, I want to know how and why.”
Zara looked at him. Her eyes were intense with passion and intelligence. “What do you want to know?”
Sam grinned. “Everything.”