The momentary distraction gave her a fresh perspective, though the water seeping into the eye cups left her vision blurry. She realized now that, despite differences in depth, the grooves and protrusions still reflected the curvature of the surrounding chamber. It was almost as if large square sections of the wall had been excised to reveal another sphere underneath, and then another beyond that, like the layers of an onion.
A sphere inside a sphere inside a sphere. Almost like Professor’s second drawing.
Inspired, she swam closer to the wall and pressed against one protruding square, about two feet on each side. When that yielded no results, she moved her fingers to the edge and tried pushing it sideways, like sliding a window open.
The stone moved laterally, but as it moved, it caused other sections to move as well.
It’s a puzzle, Jade realized. Like an enormous inside out Rubik’s Cube. Move one piece and the whole puzzle changes. But what’s the solution?
The answer was so obvious, she felt stupid for not realizing it immediately. The key to the puzzle, and the combination that would unlock the door to the vault, was embodied in the riddle of the Borromean Rings.
She swam sideways, trying to take in as much of the inside out orb as she could. Now that she understood what she was supposed to do, she had no difficulty visualizing the finished product.
There were four layers in all. The deepest was a perfect sphere. The squares of varying thickness would have to be moved around to form concentric circular bands that corresponded to the arrangement in the drawing Professor had shown her. None of the square sections was perfectly flat, nor were any two the same, even those that were of the same layer. Some of the edges met perfectly, while others differed by as much as an inch.
The longer she studied it, the more obvious the solution became.
I can do this. But I need time.
The burning in her lungs and the involuntary spasms in her chest told her that she was already out of time. She needed to breathe, needed to be out of the cold water. She followed the safety rope up through the murk to the top of the spherical chamber. There was a small air pocket there, supplied by the opening through which she had entered, and she floated there for a moment, greedily sucking in fresh air. The rope hung down a few feet away, marking the location off the exit. She could just pull herself up, back into the passage, crawl back and tell Professor what she had discovered. They could come back with SCUBA gear, wetsuits and high-powered lanterns…maybe sneak them in after nightfall. The Vault wasn’t going anywhere, after all. What was another twenty-four hours?
I can do this, she thought again. Right now. I can open the vault.
She stared at the opening. I should tell him.
And if he says no?
He probably would, but in their particular working relationship, she was the boss, not him.
“Hey!” She directed her shout up into the opening. “Can you hear me?”
She heard Professor’s voice a moment later, hollow sounding, like someone speaking into a tube. “Jade?”
“I found something. Give me a few more minutes.”
There was a long silence, so she called out again. “Did you hear me? I found something.”
There was something different about the way her voice echoed down the passage, and a few seconds later, she realized why when Professor’s face appeared in the opening above. “What did you find?” he asked.
“I know how to open it,” she said, through chattering teeth.
“Jade, this wasn’t the plan.”
“Trust me. This will only take a minute.”
“That’s what you said a minute ago. Your lips are turning blue. Come out. Now.”
“No, they aren’t.” She dumped the water from the eye cups and jammed them back into place. “Be right back.”
Before he could protest further, she ducked under and went back to work. She darted back and forth inside of the spherical chamber, moving one section left, then another down, then another left.
This time, there was no uncertainty in her actions. She went immediately to the wall and began pushing the square sections this way and that, connecting matching layers to form bands that would encompass the chamber. The stone sections moved easily, with only minimal resistance, hardly what she would have expected from a limestone cave submerged in water, but then this was no mere cave. It was a Vault for the Ages, built to withstand the passage of thousands of years.
The comparison to a Rubik’s Cube was apt, since each time she moved one of the stone sections horizontally or vertically, it would affect everything else on the same plane, but she quickly figured out how to use this to her advantage. Fortunately, this puzzle was a lot simpler than the multicolored-cube. In thirty seconds time, she completed one of the bands, and saw in her mind’s eye the sequence of moves she would have to complete to finish the other two.
Breathe!
She swam back up to the air pocket, breaking through the surface with a splash and a gasp. “Professor?”
She tried to shout it, but her teeth were chattering uncontrollably and she could barely get the word out.
No answer. She searched the top of the air pocket, trying to find the opening or at the very least, the dangling safety line, but found neither.
A cold fist of dread slammed into Jade’s gut. She reached for the rope knotted to her climbing harness and began frantically pulling in the line, even though she knew what she would find. Sure enough, after pulling in twenty feet of sodden rope, she reached the end, which had been severed neatly, as if by a pair of scissors.
“Damn it!”
As she had maneuvered the pieces of the three-dimensional puzzle, reorganizing the stone squares into the ring-like bands, she had inadvertently covered the opening overhead and in so doing, sliced through the safety line. She was cut off from Professor and Shah. Worse, she was trapped inside the sphere, with only one way out.
That wasn’t strictly true. If she moved the stones in the right sequence, she might be able to uncover the opening again and get out, but that would mean trial and error, a time-consuming process, and time was not something she had in abundance — and when it was done, she would have to start the puzzle all again.
No, practically speaking, the only way out was to align the rings, solve the puzzle and open the vault.
She tried to inhale deeply to fill her lungs again, but the cold had left her muscles rigid, and she was only able to take a shallow stuttering breath. It would have to suffice.
She swam back down, attacking the puzzle with frenetic urgency. Shift right. Slide down. Shift right. Slide up.
Breathe!
No. Almost done.
Shift. Slide. Shift.
Breathe.
A spasm racked her chest. She blew air into her cheeks then breathed it in, trying to fool her autonomic nervous system. It didn’t really work, but the attempt dislodge the plastic bottle lens over her left eye, and as it drifted away, a rush of frigid water pressed against her eyeball.
Keep going. Almost done.
Slide, shift, push… And then, she saw that only one more move remained. When she pushed the stone into place, the puzzle would be solved and the pattern of interwoven rings would be formed. What happened after that would be, as Professor had indicated, unpredictable.