Free Deep Shadow by Randy Wayne White

hit bottom. Wrong about that, too. So I recalculated, and made another attempt to find the ledge, both hands extended, feeling my way.
    Nothing.
    I was disoriented. The sediment was so thick there was the illusion that I was descending, not traveling on a level course. The silt, as it boiled around me, appeared to be siphoning downward, too.
    Or was it illusion?
    I swam blindly for another few seconds before I stopped, and told myself to calm down, to think. I checked the depth gauge attached to my buoyancy compensator vest—a BC. The gauge was a simple recreational-dive computer, with a needle and precise green numerals. Even so, visibility was so poor I had to hold the thing against my mask to read it.
    48 ft.
    Damn it!
    It wasn’t an illusion. I had been descending. Without landmarks to guide me, I’d been following the lake’s rim downward toward the mouth of the underground river.
    My brain analyzed the inference. If silt was being drawn downward, there was a reason. It meant there was a subtle, siphoning current. I had been swimming with the same current, following the path of least resistance.
    I took two slow, measured breaths. Because I no longer knew up from down, I cupped my regulator and watched the bubbles. Next I jetted a burst of air into my BC, then followed the bubbles slowly toward the surface, exhaling as I ascended, left hand extended above my head, right hand holding the pressure gauge near my mask.
    When I got to twenty feet, visibility had not improved. I purged my BC until buoyancy was neutral, then hung suspended for a few seconds. Where the hell had the lake’s bottom gone?
    I spun around, searching . . . and was instantly disoriented again.
    Granules of sand swirling before my eyes assumed the pattern of distant stars . . . then zoomed closer, thick as a soup of protoplasm. I knew I had to surface to get my bearings. When I burped more air into my BC, it reacted with a thrusting space-shuttle jolt and began to transport me upward.
    At ten feet, I stopped again, surprised by another thunderous rumble. Water conducts sound more efficiently than air. The rumble came from beneath me, vibrating through flesh, resonating in bone.
    Another landslide?
    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