“He used a double shell, made of sandstone and marble,” Tom said.
Sam glanced at him and nodded. A slightly wry smile forming on his lips. Sometimes his friend did listen to history. “Brunelleschi’s dome would consist of two concentric shells, an inner one visible from within the cathedral nested inside a wider, taller external dome. To counteract hoop stress, he would bind the walls with tension rings of stone, iron, and wood, like hoops on a barrel. He built the first 46 feet in stone, after which he continued with lighter materials, such as spugna and brick. He also managed to do so, without the use of conventional, ground-based scaffolding.”
Zara interrupted. “This is a great history lesson, but I don’t see how any of this is going to help us reach the top of the oculus?”
Sam smiled. “Look at the size of this dome. It’s not quite as big as Il Duomo di Firenze, but only by a dozen or so feet. That means the engineers and craftsmen who built this extraordinary structure must have overcome similar obstacles during construction.”
Zara asked. “You think this is a Duomo?”
Sam smiled. “I’m certain it is.”
“Again, how will any of this help us?” she asked.
Sam smiled again. “Because you have to picture this place without any water at all. What’s on the other side of the interior dome of the Duomo?”
Her eyes hardened. “The cloistered vault!”
Chapter Seventy
Zara watched Sam slip into the cool water. Her face was a mix of anticipation and someone preparing for disappointment. She saw Sam swim gently along the surface to the edge of the dome, where the pendentive met the water. The large muscles in his back formed sharp angles with each stroke. He moved along the surface in a counterclockwise direction.
Tom dipped into the water on the opposite side of the island. Dropping like a pin and then surfacing moments later. He turned to face Sam. “I’ll bet you a beer I’ll find the entrance first.”
Sam smiled. “You’re on!”
Zara laughed. They were such typical boys. It was like watching children at the beach looking for hidden treasure. Only in this case, the treasure was real, the pirates were real, death was real, and the outcomes possibly resulting in the life and death of the human race.
And still, they looked like they were having fun.
Sam and Tom disappeared below the surface. The light in the dome faded quickly as the blue haze from their DARPA suits became buried in the water. Within a minute, the dome had turned to a deep gray, and eventually into total darkness. She stared at the water. Or more accurately, where she believed the water should have been, waiting for the light to return. She didn’t wear a wristwatch and had no means of measuring the time, but it seemed to stretch.
When she was certain more than a few minutes had passed, she sat down. Zara felt the gallop of her heart, as the claustrophobia snuck in. She breathed in deeply, trying to resist the terror that was struggling to overcome her.
She forced herself to smile. Faking it is half the battle. She knew they hadn’t drowned. Not yet and not both of them. They had probably found something. An underwater ledge or another cavern. Anything to let them breathe for a while and continue to explore.
She stood up again, finding she was becoming angry with both men. If they have found something, why not come up and let her know? Why make her wait, and suffer — in total darkness?
Around what seemed like ten minutes later, but might have been much less, Zara spotted the tiniest of blue dots in the water below. She smiled as she watched it slowly surface, bringing with it, the familiar blue glow.
A moment later, the island lit up with the strange, blue light.
Zara turned around. The island was just about glowing. What the hell? She glanced at the water where the blue light was still approaching. The second light was coming from somewhere entirely different. She looked up and smiled. Leaning on the edge of the oculus, eighty plus feet above, she saw Sam Reilly’s face.
She squinted her eyes to make out the shape. Even at that distance, the man appeared to have an arrogant smirk of self-confidence. “Morning, Zara. I told you I’d get to the top of the dome! How about you come join me, the view’s fantastic!”
“Looking forward to it!” she shouted back.
She smiled and a moment later Tom surfaced. His face cheerful as he quickly boasted, “I won. I found it first!”
I’m stuck in some subterranean hell hole with two children!
Zara asked, “You found a way out?”
“No. I found a way to the top of the dome. Of course, Sam couldn’t stand to be beaten so he asked for a double or nothing bet that he could reach the top of the dome before me. I don’t know if I’d go quite that far, yet, but I did find a way to the top of the dome.” Tom smiled. “Have you been waiting long?”
She shook her head and smiled at his concern. “Now what?”
“Now if you follow me, I’ll take you to the top of the dome, and we hope like hell the ancient tunnel leads somewhere worth going.”
Chapter Seventy-One
Zara dived downward into the depths of the subterranean lake. She followed the blue light where Tom swam in front of her. It reminded her of a ghoulish apparition as the pressure built up in her ears. She tried to swallow and move her jaw, anything to relieve some of the pressure in her middle ear. The pressure changed and she was able to descend without any further pain.
The entrance was thirty or maybe even forty feet below the surface of the water. It was an arched door, which led to a narrow staircase. Apart from being submerged, the opening appeared no different than any of the thousands of mediaeval arches and stone stairs found throughout Europe. She followed Tom who swam quickly through the arch and into the stairwell.
You’ll have to swim quickly once you’re inside or you’ll never reach it! She recalled Tom’s words to her before diving.
Zara reached the top of the archway and pulled herself through. She’d reached the deepest point of the dive. Now all she had to do was live long enough to reach the surface. Inside, the series of identical stairs fit snugly between the inner and outer dome within a space no wider than two feet. The stairs ascended steeply in a clockwise direction.
She swam through and began the dangerous journey, alternating between kicking off with her feet and pulling herself upwards by drawing on the stairs, in a similar manner to an astronaut maneuvering around the Space Station.
Her head throbbed. Oxygen starvation was starting to affect her brain. She focused on the blue light ahead. No longer able to discern any visible image of Tom, her mind imagined it really was a ghost leading her toward something.
But was it where she wanted to go?
Was it a good spirit, or evil?
Her mind struggled to comprehend what she was trying to achieve. The space was dark with solid masonry walls on either side as she ascended in a continuous curve. It was impossible to know how far she climbed. She imagined the stairway wrapping all the way around the inner dome until it made a full circuit, possibly even multiple laps. She settled into a rhythm and soon the discomfort in her chest and blurriness in her mind all ceased to matter. She was moving, ascending, and that all had to mean something good, right?