Whatever the case may be, one of the stones definitely didn’t belong there.
It was made of obsidian.
The rest of the stones were predominantly Jotnian sediments — a group of Precambrian rocks more specifically assigned to the Mesoproterozoic Era — predominantly a white quartz-rich sandstone or shale, with the silty seabed a mixture of mica and clay.
The result was a pitch black sphere on a bed of white stones.
Tom studied the out of place piece of obsidian. The entire surrounding geology of the White Sea was Jotnian sediments — and that meant no volcanic stone nearby.
Someone had gone to great efforts to shift the large piece of black volcanic rock to this location. Obsidian was used by a number of civilizations since the dawn of the Stone Age for a variety of purposes. The igneous rock was valued in Stone Age cultures because, like flint, it could be fractured to produce sharp blades or arrowheads. Like all glass and some other types of naturally occurring rocks, obsidian breaks with a characteristic conchoidal fracture. It was also polished to create early mirrors.
But the fact remained; only one group of people ever went to the effort of moving large amounts of obsidian stone for building purposes — the Master Builders.
Tom stared at the stone, as though it might reveal the correlation between Ben Gellie, the ancient Russian cult, and the Master Builders.
Modern archaeologists, he recalled, have developed a relative dating system called obsidian hydration dating, to calculate the age of obsidian artifacts.
He wondered what such a reading would say about the door — if that indeed was the dark sphere’s purpose.
“Well?” Tom asked. “What do you think?”
“You want to know if we have the right place?”
“Yeah.”
“There’s only one way to find out.”
Tom allowed some air into his BCD until he reached neutral buoyancy. He stopped next to the dark sphere, placing his hands in a precise location, two thirds of the way toward the eastern edge.
He increased the pressure.
Nothing happened.
“What gives?” Tom asks.
“Try the opposite end of the door,” Genevieve suggested.
Tom set up his hand positions, gently pushed inward, and felt the massive stone give way without any resistance.
The stone swiveled inward.
Revealing a clear tunnel of obsidian.
Chapter Thirty-Four
Tom switched on his flashlight and swam through the opening.
Genevieve waited on the outside in case something went wrong with the mechanism. It was thousands of years old, after all.
Inside, Tom placed his hands in the exact same position on the sphere, this time closing the door completely from the inside. He took a deep breath, concentrated, and found the same strange grooved indentation on the opposite side of the door.
He repeated the process and the door swiveled open once more.
“We’re good,” Tom said. “Let’s see where it leads.”
“All right.” Genevieve glanced up above, where the Zodiac had cut the engine. “Right on time. It looks like we might have company.”
Tom followed her gaze.
There were already divers entering the water.
“How do you want to play this?” he asked. “Inside the tunnel or out?”
“Inside. We can keep any number of them at bay inside the tunnel. Out here and outnumbered, we’re more likely to get surrounded.”
“Agreed.”
They swam through the opening and Tom quickly closed the ancient door.
Inside, the tunnel headed upward until it reached a dry landing space. He focused the beam of his flashlight down the tunnel. It looked slightly curved, like it was part of a spiral. Tom glanced at his dive computer. It had an inbuilt Air Quality Particle Counting Meter — the same sort of thing a miner might carry that detects oxygen and carbon dioxide levels, as well as the presence of any number of toxic chemicals or gases. The reading showed seventy-eight percent nitrogen, twenty-one percent oxygen and zero point zero four percent carbon dioxide — or roughly the equivalent ratios found in the normal, breathable, atmosphere. Last, the computer was showing no chemical, radiological, or biological threats.
Tom broke the suction on his full faced dive mask. “The air’s safe.”
Genevieve followed suit, removing her weight belt, dive tank, and flippers. “Good. I really wasn’t all that keen on walking to the center of the labyrinth with our SCUBA gear.”
They removed their MP5 submachineguns.
The weapons were used by elite forces around the world specifically for their reliability after water submersion. One could leave a loaded MP5 in a 44-gallon drum of water for a month, come back, pick it up and fire all thirty rounds without a single misfire.
Tom set the ambidextrous selector to F — for fully automatic.
And waited for their enemies to come.
Chapter Thirty-Five
They waited a full hour.
Tom felt his heart race. His breathing was uneven, his concentration fixed, and his jaw set. He and Genevieve had their MP5 submachineguns ready to fire. But the obsidian door never opened.
She said, “Looks like they’re not coming.”
Tom considered that and shrugged. “Or they’re waiting us out?”
Genevieve lowered her MP5. “Or they’re waiting us out. Either way, we need to keep going.”
“Agreed.”
With their diving equipment dumped on the dry ledge of the tunnel, they made their way toward the center of the labyrinth.
The obsidian passageway meandered in an alternating series of curves, forming adjoining spirals. Tom shined the beam of his flashlight in both directions, checking for signs of other people. There were none. For all he knew, they were the first to enter the labyrinth since 1975. His eyes searched the mysterious ebony colored, glassy walls of the tunnel for any sign or purpose — they were entirely blank.
He checked his compass.
They were heading in a generally northern direction.
Tom and Genevieve continued for another twenty minutes. All the time the tunnel seemed to keep curving inward to the left, before it angled sharply to the right, opening up to a new spiral. He glanced at his compass again. They were headed south, but that didn’t matter. They were in a labyrinth. He’d seen plenty of labyrinths since he was kid. It didn’t matter what direction you were heading. The path could turn back on itself and turn around again.
He put down the compass.
There was no need for it. Unlike a maze which had complex branching multicursal paths to choose from and was designed to disorient and confuse its users, a labyrinth, by definition was unicursal with a single path to the center, and one entrance that doubled as an exit. A labyrinth was unambiguous with no navigational challenge.
His mind returned to the oldest purpose of a labyrinth — to protect something of value at its center.
A would-be thief might attempt to steal a prize at the center, but it would be extremely difficult to try and escape from it, because the entire process takes so much time.
It was nearly thirty minutes before they reached the center of the labyrinth.
Tom rounded the end of the spiral, which then turned in the opposite direction like one giant horseshoe, before opening up to a large domed vault — not a vault, a perfect sphere — with a diameter of fifty feet.
An obsidian bridge stretched across the room, revealing the levels of the sphere below. A single set of obsidian stairs led all the way from the base to the ceiling in an ascending spiral that hugged the natural curvature of the spherical room.