"Stay here a minute, dear, I want to see how far the tide is in." The double winding of the cave made it hard for me to judge at a glance; it was only when I came to the piece of straight passage leading up from the sea that I could judge. From the time I left the treasure chamber of the cave the water got deeper and deeper as I went, but the difficulty was not in this way; I knew that so long as there was headway I could swim for it and take Marjory with me. But when I came down the straight, my hopes were altogether dashed. As the floor dipped towards the sea so did the roof in much greater degree. I knew that there was one place where at low water there was only barely headway even when we stooped low; but I was not prepared for what I saw. The water had already risen so far that this place was, from where I stood waist high in water, obliterated; the rocky roof sank into the still, level water. For a moment I considered whether it would not be best to dive through it. I had the cord to guide me, and I knew that towards its mouth the cave roof rose again. But then there was Marjory. She was not like myself an accomplished diver. It might be possible if the worst should come to the worst to draw her through the water-choked piece of tunnel by the guiding cord. But if the cord should break or anything go wrong.... The thought was too dreadful! I hurried back to Marjory to see how far it might be advisable to make the attempt, however dangerous, rather than be drowned in the deepening water of the cave, or asphyxiated if the space left were too small to allow us breathing till the falling of the tide. I found Marjory standing on the shelf of rock, to which she had climbed by the aid of the San Cristobal figurehead. She was holding up the torch and examining carefully the walls and roof of the cave. When she heard the splash of my coming through the water, she turned; I could see that though her face was pale she was very calm and self-possessed. She said quietly: "I have been looking for high-water mark, but I can hardly see any sign of it. I suppose in this dark cave, where neither seaweed nor zoophyte exists, there is no such thing. Unless of course it be that the whole cave is under the water line; in which case we must be ready for the worst." As she spoke she was raising the torch till its light illuminated, so far as was possible, the extreme angle of the cavern where it ran up to a sort of point. I scrambled up beside her, and making use of my greater height, took the torch and keeping it away at arm's length put my hand into the narrowing angle. I had a sort of secret hope that there might be some long crack or rift which, though it might be impossible for our bodies, might still give us air. Any such half-formed hope was soon shattered; the angle of the cave was in the solid rock, and there was no fissure or even crack beyond.