From extremity to extremity, it must be, I believe, about five miles.
"But now follows the part of my story that I do not profess to explain.

I marked in my mind the nearest path to the sea, which was to the north-east--the path I actually pursued--and descended; and then I became aware that the feeling I had experienced before was not purely physical--that there _was_ a taint of a real kind in the air, which strangely affected the emotional atmosphere.

I felt helpless, bewildered, sickened.

I descended, however, from the platform, and walked straight, in what I had determined to be the right direction, when, just as I was about to scale the wall, heartily glad to be out of the place, I was--not exactly called, for there was no sound--but most unmistakably ordered to look round.

Am I clear?
The sensation produced mentally and emotionally was precisely like the receiving an imperative order that one has neither power nor inclination to resist--so strong and sudden that I kept thinking that my name had been called.