Free Deep Shadow by Randy Wayne White Page B

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.
    I banged the oyster shell against my own tank, parroting the signal . . . then received a different signal in reply.
    Tap . . .TAP . . . tap.
    It was Tomlinson. Had to be. Tomlinson, the blue-water sailor, the maritime minimalist. He was attempting Morse code. The man had been studying code for nearly a year, inspired by a late, great friend who had railed against our growing dependence on technology.
    I’ve been a devoted user of shortwave radios since childhood, but I’m not a student of Morse code. I know a few basic shorthand signals, but now was not the time to test my skills. We had less than twenty minutes of air left. Subtleties of communication would have to wait.
    I returned to my digging, bulling chunks of limestone to the side, then using the oyster shovel to scoop a dent in the sand. I kept at it until a sound within the wall caused me to pause once again.
    It was an alarm sound, the rapid clang-clang-clang of a fire bell. Tomlinson was telling me to stop digging.
    Why?
    I could think of only one possibility: My digging was somehow threatening the stability of the space that was providing them refuge.
    Maddening! If I couldn’t dig, how did Tomlinson expect me to free them? After several seconds of silence, he tried Morse code again.
    Tap . . .TAP . . . tap.
    I forced myself to concentrate. The louder clanks, I decided, were dah s in Morse. The faster, lighter raps were dit s.
    Tap . . .TAP . . . tap.
    Was it the letter R ? Yes, an R . R is the most common Morse abbreviation. Even I recognized it. R stands for “roger”—“signal understood.”
    It was Tomlinson’s way of beginning a dialogue.
    I