It was necessary now to move towards the river, and the task seemed impossible.

I could see no footholds, save two frail pegs, and in the corner between the wall and the roof was a rough arch too wide for my body to jam itself in.

Just below the level of the roof--say two feet--I saw the submerged spike of rock.

The waters raged around it, and could not have been more than an inch deep on the top.

If I could only get my foot on that I believed I could avoid being swept down, and stand up and reach for the wall above the cave.
But how to get to it?
It was no good delaying, for my frail holds might give at any moment.