He had entered the crack long before I had reached the top, and his progress was twice as fast as mine.

When I emerged on the topmost shelf he was scarcely a yard behind me.

But an overhang checked his bulky figure and gave me a few seconds' grace.

I needed it all, for these last steps on the shelf were the totterings of an old man.

Only a desperate resolution and an extreme terror made me drag one foot after the other.