We soon swam our way over to where the tunnel entrance was supposed to be. My running shoes touched a slippery rock, and I guided Myra to it. We rested a moment while I switched on the flashlight and swept the beam down among the submerged rocks. The water was a murky green, filled with tiny particles that glowed white under the dim light. The beam reached down only a few yards, but between a cluster of four weed-covered volcanic rocks I could see a narrow gap that dropped away into darkness.
        Myra finally spoke, removing the mouthpiece momentarily. "D-Down there?" she asked. Her eyes were so wide.
        "I think so," I said, staring downward. Diving into that gap seemed like pure madness. Part of me wanted to give up, to just close my eyes, let the air out of my lungs, and sink down until I was no more. The thought that Dan was really gone . . .
        But I had to finish what he had started. That was important to me now. And I also had to do something with Myra. I couldn't just leave her here alone.
        I took several deep breaths to oxygenate my blood. Then I took a last breath and dived down. It wasn't easy going; my shirt, jeans and running shoes pulled against my every movement. And Myra hanging to my belt made it almost impossible to complete a full stroke or to kick vigorously. But she managed to help a little, swimming with her one free hand and her feet. She had lost her shoes on the swim over.
        The flashlight beam swung crazily, probing deeper into the black recess. The hole led down through gently waving carpets of seaweed that grew like green hair over the rocks. I grabbed for the seaweed and started pulling myself down the rock face, hand-over-hand. Frequently I stopped to take the regulator from Myra's mouth and draw a couple of deep breaths, before returning it to her mouth and clearing the mouthpiece of water by briefly depressing the purge valve. I allowed myself a momentary feeling of pride at remembering enough of the dive manual to get us at least this far.
        We had one bad moment where Myra pulled back, screwing her eyes shut and pointing to her ear. I realized she was having trouble equalizing the air pressure in her Eustachian tubes, so I had her ascended slightly. Still clinging to the seaweed, I demonstrated what to do by pinching my nose and trying to blow through it. It had taken me a fair amount of practice to get the technique down properly at the health club where I usually did my swimming, and I feared Myra wouldn't be able to pick it up quickly enough, especially under these conditions. But after copying my motions, her pained squint relaxed and she nodded. I continued to lead her slowly down the rock face, making sure she cleared her ears periodically.
        The dark recess narrowed and made several twisting turns. In one place it was too narrow for both of us to pass through at once. There I forced myself to relax for a moment. I drew as much air into my lungs as I could before indicating to Myra to go through first. Eyes wide with fear, she began pulling herself down through the passage, while I aimed the light past her. Her necklace caught on a projecting sliver of rock, which cut it like a knife. The pearls slid from her neck and floated like a brief snow flurry into the darkness below.
        Myra didn't take long to crawl through the narrow passage, but I felt my heart pounding as my source of oxygen slipped out of reach. I followed quickly behind her, grabbing the regulator and sucking air greedily as soon as I was through. I realized then that we no longer a clear path directly to the surface if anything went wrong.
        After the narrow gap, the passage curved up and began running horizontally—toward the shore, I presumed and hoped, since by this time I had no idea which way we were facing. The rocky passage had become a recognizable lava tunnel, almost perfectly cylindrical with rough walls. It was nearly six feet in diameter but to me it felt chokingly narrow. The water temperature had also dropped several degrees, causing us to shiver and cling to one another for warmth. Our bubbles collected in large, distorted balloons wobbling against the ceiling. The water was clearer down here, almost free of floating particles. The vegetation had thinned out completely, and the only living things we saw were several small fish and a blue crab, which skittered on ahead of us as if leading the way.
        I anxiously checked the air gauge, alarmed at the rate we were consuming air. Two very nervous people on one small tank made for a short supply. There was less than half a tank left, and I realized we wouldn't have enough to make it back. I could feel Jason staring at the air gauge too, and knew that he was lurking dangerously close to the front of my mind. If I let Jason take control now, Myra wouldn't stand a chance. . . .
        So I forced myself to control my breathing, taking long, slow, deep breaths. I wished fervently that I hadn't had to bring Myra along with me. Dan should have been in charge here, not me. But now not only was I having to plan and do everything, but I had someone depending on me so I couldn't even let Jason take over. This wasn't fair, either to me or to Myra. Yet what choice did I have but to go on? Surely I'd find someplace soon where I could let Jason take over. . . .
        The first true indication that the tunnel was curving upward was a relaxing pop in my ears. Myra seemed to notice it too, her large brown eyes showing first alarm and then obvious relief through her mask. Then the bubbles collecting on the ceiling began to wobble their way forward ahead of us, seeking higher elevation. The lava tunnel continued to climb and we swam eagerly forward. To avoid damaging my lungs on ascent, I started releasing a small stream of bubbles from my mouth—something else I'd read in the dive manual. I pointed out the bubbles and made sure Myra also kept breathing out.
        And suddenly there it was there above us, the shimmering plane that signaled air. We ascended rapidly and burst through the surface with a loud splash, laughing and crying with relief and gasping for air as if we hadn't taken a breath since we made our descent a lifetime ago. I briefly swung the flashlight beam along the shore, then struck out for it, hauling Myra along. We struggled up onto the smooth rock tunnel floor and rolled over on our backs, still gasping for air.
        Only then did Myra release her death-grip on my belt and shrug the tank off her back. For a moment she just looked at the disturbed surface of the pool we'd just crawled from. Then she put her face in her hands and started sobbing quietly.
        I also stared at the pool, pretending not to notice Myra's crying—I didn't know what to say or do. I concentrated on holding the flashlight beam on the rippled surface of the water while I waited for my breathing and heart rate to slow.
        I heard a brief, soft sound from nearby. I sat up, holding my breath and motioning Myra to be quiet. But the sound was gone now. It had sounded like a heavy sack slowly dragged across rock.
        "I heard a—" I started, then heard it again, from behind. I quickly turned around, playing the yellow beam over the tunnel behind me—
        And I found myself staring into a huge, lidless, dead black eye. It was as big across as I was tall. And below it, two eyeless snakes, quivering and probing, slithered across the tunnel floor, heading directly toward me.