Out the window to his left, Tom could see that the mole was only just floating above the surface of the whitewash. It floated there for a few seconds, being pulled slightly backwards by the flow of water pouring in behind them, before becoming caught in the downward hydraulic of the river, and pulled off the next ledge.
James laughed, like a kid on a ride, “Here we go again!”
The mole dropped off the second into another rock pool. This time, the unnatural flow of the large river spun the mole around in a clockwise motion.
By the fifth revolution, they slammed into the rock at the edge of the pool. In an instant, Tom shoved the two throttles forwards, sending the tank tracks spinning, until they met traction on the rock and sent the mole shooting up and over the next drop.
Tom felt the entire contents of his stomach reach his head, as they free-dived into the deep pool of water at least ten feet below.
Slamming into the deep water, the mole’s giant drilling nose acted like a high diver’s hands as it broke the surface tension, before submerging nearly twenty feet below.
The mole popped its head above the water again, and started to gently drift down the river at a leisurely pace. James unbuckled his seatbelt, laughing like a demon as he leaned forward, and said, “That was great fun. Let’s go do it again!”
Tom shook his head in wonder. Some people don’t even know when to be scared. Aliana, on the other hand, looked as though she might spew all over the mole, but was purposely forcing herself to sit up and take in her surroundings.
“How you doing?” he said, looking at her.
“Fine… Are we done with the rollercoaster yet?”
“Almost. According to this, we should be just about to meet up with the part of the river where Sam has surveyed.” The river, now gradually moving forward with no ripples or violent waves, looked like it went on forever. “Is this a more agreeable pace for you?”
“Much, thank you,” she replied.
Tom left the tracks spinning slowly in a forward momentum, just enough to keep them facing forward as they drifted down the river.
Up ahead, the river appeared to just cease.
But rivers never end in a tunnel; they end in the ocean or large inland lakes.
“Can anyone see where the river goes after this?”
James casually buckled his seatbelt again. “I thought you said you had a map?”
“It might have been just a little wrong,” Tom replied.
“How wrong?” Aliana asked, worried that although there were no ripples, the current seemed to be increasing again.
“Wrong enough that I only have one guess where all this water is disappearing to.”
They were nearing the end of the river, and the flow was fast — like when it was about to drop off the edge of something.
Tom now recognized the distant sound of constant thunder up ahead.
“Hold on everyone.”
Just before dropping off the end of the river into the unknown below, Tom pulled on a lever above his head, and the doors to the air ballast opened to full. The heavy mole sank, like a giant stone, as he pushed throttles fully forward again.
Down, down, the mole submerged. In front of him, Tom read the depth gauge reach 80 feet, before he saw what he was looking for.
An opening appeared at the base of the deep tunnel — too small to accommodate the vastness of the river. There, most of the water toppled over the top of the large rock face, whereas some still flowed below it.
The tank tracks reached the gravel bottom with a jolt and kicked the mole into life as it started to drive along the bottom of the river.
“Think skinny thoughts!” Tom said, as he lined up both tank tracks to drive straight through the hole.
A loud thud could be heard as the mole’s tank tracks smashed through the rocky edge of the opening, and then they were out the other side. Above them, the sound of the waterfall, now on their side of the 80-foot rock, could still be heard hammering the water above them.
Tom drove confidently along the now completely submerged river system. “Ah, now, we’re in the same subterranean river that Sam mapped earlier.”
An hour later, the small team looked through the clear bulletproof dome above their heads to see the remains of a mining platform inside an enormous cavern.
“This must be what Sam said was called the Mahogany Cavern. Up there you can see the dive platform they were working on.”
“Are you sure they’re still out?” Aliana asked, noticing the lights within the cavern were still running.
“Pretty sure, but don’t worry. — we’ll be ready if they come,” James said.
Tom drove further downwards, towards the exit tunnel.
The tunnel was longer than he’d imagined it, and for a moment Tom worried that he’d taken the wrong one. But then the depth of the tunnel started to decrease, until the tank tracks above their heads were occasional scratching on the ceiling of the tunnel.
The mole slowed, and then, like a four-wheel drive starting to become bogged in the mud, the tank tracks seemed to be turning at a rate faster than they were moving.
“You want me to get out and push?” James asked.
“Not just yet,” Sam replied. He pulled the lever above his head, which opened up every air compartment available, causing the mole to become extremely negatively buoyant.
The tank tracks instantly sunk deeper into the sandy bottom with a heavy crunch and began catching again. And then they were through to the other side.
Where the Mahogany Ship waited for them.
They approached the Mahogany Ship from the side, and quickly saw the large hole in its side, where Sam had been entering her bow. Aliana stared out the porthole to her right, where the ship stood. “Tom, you know what Sam would have used when he was diving here. Any sign of his equipment?”
“Not yet. I haven’t seen anything. And seeing nothing can often be a good thing when we’re talking about searching for a lost cave diver.”
“Sam’s not drowned,” James interrupted, frustration clearly displayed on his face. “There were a number of caverns full of air, and pockets of air throughout the tunnels on the way in here. There’s no way Sam could have drowned here. Heck, I bet the athletic bastard, could have managed the trip we just made, holding his breath between the underwater sections.”
The statement was ridiculous, but Aliana was grateful for his reassurance.
“Now what do we do then?” she asked.
“We have a look at Rodriguez’s fake Mahogany Ship, and take his gold!” James’s eyes lit up with excitement.
“What about Sam?” Aliana asked, feeling as though she were the only person capable of staying focused on their primary mission — to save Sam.
“If I know Sam, he would have taken the same route out that we just took to come in,” James said.
“Then why didn’t we see him?” she argued.
Tom switched both tank track electric motors to off, parking the Mole, and then suggested, “Maybe he was already out?”
“Not likely. We would have seen some sign of him at the river,” Aliana said.
“Come on, let’s get the gold,” James pestered, with a big, stupid grin.
“Are you serious?” Aliana’s eyes stared at him.
“If Sam did escape, he would have left a note or something for us on board the Mahogany Ship. Besides, I’d really like to see to what lengths Rodriguez has gone to bring us here.”
“All right,” Aliana said, “but only so we can see if Sam left us anything to go on. Then we’re back to searching for him.”
“Agreed.”
At the rear of the vehicle was a small airlock chamber, large enough to allow just one person at a time to exit the mole, in full dive gear.
James was the first to leave, followed by Aliana, and Tom agreed to stay and keep guard. If Rodriguez and his men came back while the other two were away, he said he would run them over with the mole at best, and at worst, block the entrance to the Mahogany Ship so that the others could escape.