J. S. Fletcher 
Sea Fog [EPUB ebook] 
crime classic

I think my first notion was that this was the cry of some animal, trapped close by, or seized by another. But on the instant it came again, and I knew it then for the cry, desperate, terrorised, of a man in deadly fear and peril. I had sprung to my elbow at the first sound: at the second I looked sharply through the opening of the chains into the ground floor beneath me. The man of the map had gone; there, plainly outlined in the bracken, was the place where he had slept, but he and his bottle and his knapsack had vanished. And at that I jumped for the gap in the outer wall and looked out on a morning thick with milk-white mist. A great sea fog had rolled up from the coast and enveloped the plain and the hills, and from where I stood all the land was wrapped in its curling vapours. At first I saw nothing; then, a stifled cry coming again …