My first entrance was at high tide, and I soon found I could do little. The tunnel penetrated far into the land, but sank downwards, so I found myself held back by the deepening water. Accordingly the next time I went at low tide, and made an interesting discovery: the roof of the tunnel sank and rose and sank again, forming pockets, as it were. All the way beyond the first pocket the roof was slippery with weed, telling me that at high tide the tunnel was full of water. It was an unpleasant discovery, for I knew that if I weren't careful I might be caught in one of the pockets and trapped by the rising tide. At the first feel of the stealing water about my ankles I beat a hurried retreat, in alarm at being snared and drowned like a rat in a trap. But I found my fear was premature. I could have continued my search for a long time yet without danger. At my third attempt I started with the tide at half ebb, so as to give myself the maximum time for exploring. I waded knee-deep up the long and winding tunnel, thrusting my lantern into every nook and cranny, and digging with my hands into the thick weeds which dripped from the walls. And so I passed pocket after pocket, and knew that the tide must soon be on the turn. I was afraid to stay much longer, but ducked under one last arch. The tunnel rose up steeply before me. I gazed above; and the swinging light of my lantern fell full upon the white bones of a skeleton. For a moment I stood motionless, gazing, while the crabs scuttled out of the light. My thought was, "Poor wretch, he must have been caught in the tide." At that moment there came a little slap of water at my feet. It was like some evil serpent of the sea thrusting out a cold, lean throat towards me, flickering about me with a cruel forked tongue, gathering itself to strike. So unnerving was the swift impression that with a cold panic at my heart I turned and fled, splashing down the tunnel to safety; and for a couple of days or more I dared not venture back, though again and again I dived into the cavern intending to pursue my search, and unravel the meaning of that skeleton. But for a while I couldn't bring my courage to the necessary pitch. The thought of being trapped there like that drowned wretch, of having my flesh eaten off me by those loathsome, hurrying creatures I had startled with my lantern, was too dreadful a prospect. I told myself that in a day or two I should regain my nerve. Meanwhile to erase the impression I set myself to accomplish a feat I had long vowed to attempt: the scaling of that great bulging rock that overbrowed Ebb-Tide Pool.