when it crashed, had compromised the integrity of the limestone hourglass. It had cleaved a massive wedge from the overhang above me. As a result, the stone stricture into which Tomlinson and Will Chaser had disappeared, although thick at both ends, was perilously thin at midpoint.
If I made a mistake with the jet dredge, if I cut too deep or in the wrong place, the lake basin’s entire limestone scaffolding could collapse.
I had returned to the place where we’d found the mammoth tusk, and Tomlinson was signaling me again.
It had become his audio signature. He was still alive, but his tapping sounded more urgent now. It wasn’t my imagination.
Ninety seconds—that’s how long it had taken me to retrieve the tanks and return to the rubble that marked where the limestone ledge had once been.
I didn’t waste time responding.
He was signaling, I knew, because he’d heard me as I wedged one of the bottles into the crevice below the rubble and then opened the air valve a half turn. There was no need for me to answer the man. Soon enough, he would hear the jet dredge cutting through the sand above him. He would know that I was doing everything I could to get him and Will back to the surface.
The decision I now had to make was an important one: Where should I start digging?
After anchoring the second spare tank nearby, I located the hose to the dredge. It hung in a limp coil beneath the inner tube, where I could see King’s legs dangling. I swam to the PVC tube, checked the brass nozzle to make sure it was clear, then touched my finger to the makeshift trigger and tested the thing.
The sudden pressure caused the handle to kick in my hand as water jetted out the nozzle, an expanding swirl of bubbles that had the velocity of a dentist’s drill.
I removed my finger from the trigger and began to search for the best area to begin excavating. I wanted to locate the exact spot where Will and Tomlinson’s bubbles sparkled up through the limestone base . . . But there was no single exit point that I could find. The air ascended from several areas of rock.
That was okay. I told myself it didn’t matter. Even if I had found a precise exhaust point, it was no guarantee that it marked the location of my friends. Like water through a leaky roof, air bubbles traveled the path of least resistance, following angles and curves, until they found an opening. The guys might have been directly beneath their bubbles, but just as likely their bubbles had traveled many yards before finding a porous area through which to ascend.
It was also possible that Will and Tomlinson had moved from the spot where the ledge had collapsed. They could have burrowed into some unseen crevice or followed a karst vent, seeking an exit, leaving a trail of trapped air bubbles behind them.
I swam to the drop-off to get one last overview of the limestone overhang. If I excavated too close to the fragile midpoint, the whole slab might shear away. I chose an area slightly inland from where the ledge had collapsed and decided that it was safer to dig from the side of the overhang instead of directly downward.
I bled every bit of air from my BC to ensure negative buoyancy, then pulled on the hose, telling King that I needed slack. I dreaded the man’s response, but I was prepared when he attempted to yank the thing from my hands again.
I tugged twice more, battling my temper and still wrestling with the temptation to surprise the man from behind and break his neck. There is a type of person who teases and taunts but always with an exacting sense of boundaries. King was one of those, and he must have sensed he had pushed me to the limit because suddenly coils of hose dropped down from the inner tube as he provided me with enough slack to work.
I raced to the edge of the overhang and used my left hand to anchor myself to a slab of limestone before squeezing the jet dredge’s trigger. The PVC pipe jolted; the hose began to snake, writhing with pressure. When I touched the brass nozzle above the rock, sand exploded around me. The laser jet of water plowed a furrow that smoked like a lighted fuse.
I began cutting at a slight upward angle, attacking the overhang as if peeling an orange. Rock and sand appeared to melt away, creating a slow landslide that dropped beneath me as I progressed. Because it was important that I knew how my work was affecting Tomlinson and Will, I stopped after only thirty seconds. After a long pause, I tapped the nozzle of the dredge against my air bottle. Eight taps—probably not timed correctly, but Tomlinson would know what I meant.
The letters
Tomlinson’s response was barely audible, but I received eight taps in response.
More likely, though, if they had actually found a vent large enough for them both to negotiate, the tunnel would angle downward toward the subterranean river, not upward toward the surface.
As I began cutting again, I glanced at the murk below my fins, thinking about that possibility. At its narrowest point, the remnants of the limestone bridge were no more than twenty feet thick. Maybe I had been wrong to try excavating from the side. Would it have been wiser to attack the overhang from beneath? I imagined myself cutting through rock and sand until my friends literally fell to safety.
My eyes moved back and forth, monitoring the trench I was digging while also considering the geology of the lake.
No . . . I couldn’t risk excavating from beneath. It was smarter to stay where I was. I had seen the ledge from the vantage point of the wrecked plane. The lake’s hourglass scaffolding was too fragile, already compromised by the plane crash. Cutting from below would be like sawing through the load-bearing beam of a house. The entire structure could come crashing down.
For what seemed a long time, I worked hard, cutting deeper and deeper with the dredge, afraid to risk a glance at my watch. Internally, I was battling a welling panic. I vented energy by attacking the overhang, clawing away boulders and fossilized shell, ripping my way into the earth.
Finally, though, I knew I had to stop and assess. I looped the hose over my shoulder and banged the nozzle against my tank. Eight taps or nine—I wasn’t certain. My hands were shaking as I listened.
Nothing.
I signaled again. Then
It was Tomlinson, but only Tomlinson, and there was no mistaking the meaning of those nine distinct bell notes. He was now sending me an SOS.
Perhaps the pilot of the wrecked plane had sent out the same signal before crashing into this lake. It was a three-letter cry for help.
I checked my watch. The orange numerals seemed inordinately bright and stabbed at my eyes. Sixty-three minutes since we had begun what should have been an uncommonly safe dive on an uncommonly warm and calm February afternoon. The watch confirmed what I feared.
Tomlinson and I had been friends for so long, we had shared so many experiences, good and bad, that I knew he would not resort to an SOS unless he was at his end. Maybe Will was dying . . . or maybe the kid was already dead. Tomlinson would soon follow.
I shouted a pointless refusal through my regulator mouthpiece.
No—I wasn’t going to let it happen. Sometimes, the most dangerous option is the only option. I had made progress digging into the side of the overhang, but it was time for a more extreme approach. I had to risk cutting into the overhang from beneath. We were out of time, and it was my last best hope. Bringing the limestone bridge crashing down atop me was preferable to what I knew was the inevitable alternative. If I didn’t free them within the next minute or two, later, much later, I would have to wait while a recovery team retrieved the bodies of my closest friend and a sixteen-year-old boy who had already suffered too much trauma in his life.
I yanked hard on the hose, demanding slack, and realized as I waited that I was at risk of biting through my
