Deep Shadow

No. The sound was different, an abrupt thud of weight, then a mushrooming silence. If a massive slab of limestone had collapsed, it might make a similar sound.

I waited, dreading confirmation. The confirmation arrived via an upward surge of displaced water and a blooming cloud of darker sediment.

The landslide had caused a section of the lake’s bottom to collapse. I knew there was a chance that Will and Tomlinson had been swept deeper by the implosion.

I surfaced in a rush. When I’d broken free of the murk and pushed the mask back on my head, I used fins to do a fast pirouette, examining the lake’s surface. I hoped to see Tomlinson and Will floating nearby, laughing in the winter sunlight, already recounting their brush with death.

Instead, the lake was a solitary disk, wind-rippled, empty.

I checked the time. Forty minutes, I’d been down. At the max, Will had twenty minutes of air left, Tomlinson thirty . . . if they were still alive.

I faced the lake’s southern shore, searching for our vehicle. It was a four-wheel-drive Dodge Ram truck, parked on a cypress ridge, fifty yards away across the water. I began calling for Arlis Futch and expected to see him exit the vehicle, hands on hips, still in a foul mood because I’d made him stay ashore.

The truck’s door was open, but there was no sign of the old man. There was no sign of life, period, save for a pair of loons V-ing toward the lake’s far rim and the ascending whistle of an osprey that wheeled overhead.

I cupped my hands and yelled, “Arlis? Arlis! Call nine-one-one!”

I waited before adding, “Tell them we need an emergency response team. Arlis! Rig the jet pump and start the generator!”

Silence.

Above, the osprey tucked its wings and dropped like a boulder. The hawk crashed the water’s surface, splashed wildly for a moment, then struggled to get airborne, gaining speed, its claws dripping . . . but empty.

“Arlis! Do you hear me? Goddamn it . . . Arlis Futch!”

Near the vehicle, a rabble of crows scattered above the cypress canopy, black scars animated on a blue sky. Something beneath the trees had spooked the birds. If Arlis was somewhere back there in the cypress grove, he wasn’t answering.

Tomlinson and Will had to be beneath me. Somewhere. There is no such thing as a bottomless lake, so I would find them. Somehow.

I cleared my mask, purged my BC, then piked downward. I let the weight of my legs push me toward the bottom.

Years ago, diving a sinkhole in the Bahamas, I swam down through a pea-soup murk only to suddenly bust through into a globe of glacier-clear water. It was like entering a crystal vault from above. The light was muted because of the gloom, but visibility was flawless.

On that occasion, I had pierced the aqueous lens of an underground spring. Fed by ocean currents, the outflow of water created a bubble of clarity. It was like discovering a secret world.

Something similar happened now, as I descended, although the change in clarity wasn’t as abrupt. Sediment was dissipating, visibility improving. It was surprising because there hadn’t been enough time for the murk to settle. It suggested that clear water was now flowing into the area from below. Perhaps the landslide had uncovered a spring.

At ten feet, I observed a vague, stationary darkness take form. It was the lake’s shallow perimeter. The ledge that held the prehistoric tusk had stood fifteen yards from the rim of a drop-off. The sandy rim remained—a relief to see a familiar landmark—but the bottom had changed. The rim soon assumed color in patterns of gray and white. I was peripherally aware of varieties of fish—bream and immature bass—that had been drawn to the disturbance.

As I drew closer, I could also see that the bottom hadn’t just changed, some of it had vanished. A section of ridge the size of a car had imploded, taking the ledge with it. From the appearance of the crater, the area beneath it had dropped about ten feet. The elevated wall had collapsed atop it and was now a mound of oolite and sand. The area was littered with fossilized oysters. The oyster shells were the size of footballs.

Then I saw something else I recognized: the prehistoric tusk. It lay bare on the sand. The thing was twice as long as I’d supposed. It was six feet of black ivory, spiraled like a corkscrew.

I swam downward, spooking fish as I approached, and lifted the tusk—it was heavy. I waited a moment, ears adjusting to the pressure, then let the artifact drop. It made a satisfyingly hollow thud. The vague percussive sound told me that the bottom was porous, not solid.

Good.

It gave me hope.

First things first, I had to mark the spot. I pulled a dive marker from my vest and secured the nylon cord to a rock near the tusk. I inflated the marker, then watched it rocket to the surface.

From a calf scabbard, I removed my dive knife. Normally, I would have been carrying something cheap—more than one diver has died because he dropped an expensive knife and chased it into the depths. But this was to have been a shallow-water dive, so I was carrying a treasured possession. It was one of the last survival knives made personally by the late Bo Randall of Orlando. The handle was capped with a machined brass knob. I used the handle now to tap on the tusk, then straightened myself to listen, hoping to hear a response.

Nothing.

I tapped again, a measured series, then gave it a few silent seconds before leaving the tusk and swimming down into the crater.

A vein work of fissures thatched the crater’s limestone floor. Tendrils of gray silt vented upward from the cracks, as symmetrical as smoke on a windless day.

A volcanic effect.

It told me yes, water was flowing out through the latticework of stone. It also told me that the area beneath me was porous, not solid—possibly not heavy enough to crush two men.

Using the knife, I began tapping on the limestone, traveling along the bottom in an orderly way. Tap-tap-tap. I waited. Tap-tap-tap. I listened.

After several attempts, I abandoned the crater and followed its outer wall downward. At the edge of the wall, the bottom angled deeper. It dropped toward a funneling darkness: the mouth of an underground river.

Again, I went through the ceremony with the knife. Tap-tap-tap. Wait. Tap-tap-tap. Listen.

Twice, I worked my way around the wall, tapping, then waiting. When I finally heard a dull Tap- a-tappa-tap in reply, I thought I might be imagining it. I wasn’t convinced until Tomlinson added a vaudeville rhythm: Shave-and-a-haircut . . . two bits.

The sound was muffled but the source familiar. Rap an air tank with a knife—it was the same bell-like sound. It told me at least one man was alive. No . . . they were both alive, I realized. I was now hearing a duo of bell sounds: Tomlinson and Will both banging on their tanks.

Tomlinson didn’t carry a knife—it was irrational, but he never did—so he must have been using a flashlight or a D ring from his vest.

The clanging was steady, not frantic, which I found reassuring. My partners were trapped somewhere under the crater floor, beneath a plateau of rock and sand, but obviously they had room enough to move their arms. It suggested that they were in a crevice or in an underground chamber that had been covered by rubble

I unsheathed my knife and began to dig methodically, pulling away rock, digging at the bottom. It was mostly sand. Frustrating. Digging a hole underwater is an exercise in futility. If I scooped out two handfuls of sand, twice that amount sieved downward and filled the temporary hole. Thinking it might be more efficient, I grabbed a pan- sized oyster shell and used it like a shovel.

It wasn’t much better. Until I returned with the jet dredge, though, a shovel was my best option. I continued digging, burning my dwindling air supply, until the clanging signal from beneath the crater changed. It caused me to pause.

I heard an articulate TAP. Tap-tap-tap . . . TAP . . . tappa-tap. Over and over, with the same careful spacing. Some sounds were intentionally louder, it seemed.