"It is very odd," I remarked aloud to Mrs. Stott.
"That it is, sir," she answered; adding, "I hope to gracious none of them mobsmen are going to come burglaring here!" "Pooh!" I replied; "there is nothing for them to steal, except chairs and tables, and I don't think one man could carry many of them away."
The whole of that day I found my thoughts reverting to those foot-marks in the snow. What purpose anyone proposed to serve by prowling about River Hall I could not imagine. Before taking up my residence in the Uninhabited House, I had a theory that some malicious person or persons was trying to keep the place unoccupied—nay, further, imagination suggested the idea that, owing to its proximity to the river, Mr. Elmsdale's Hall might have taken the fancy of a gang of smugglers, who had provided for themselves means of ingress and egress unknown to the outside world. But all notions of this kind now seemed preposterous.
Slowly, but surely, the conviction had been gaining upon me that, let the mystery of River Hall be what it would, no ordinary explanation could account for the phenomena which it had presented to tenant after tenant; and my own experiences in the house, slight though they were, tended to satisfy me there was something beyond malice or interest at work about the place.
The very peace vouchsafed to me seemed another element of mystery, since it would certainly have been natural for any evil-disposed person to inaugurate a series of ghostly spectacles for the benefit of an investigator like myself; and yet, somehow, the absence of supernatural appearances, and the presence of that shadowy human being who thought it worth while to track my movements, and who had at last left tangible proof of his reality behind him in the snow, linked themselves together in my mind.
"If there is really anyone watching me," I finally decided, "there must be a deeper mystery attached to River Hall than has yet been suspected. Now, the first thing is to make sure that some one is watching me, and the next to guard against danger from him."
In the course of the day, I made a, for me, curious purchase. In a little shop, situated in a back street, I bought half a dozen reels of black sewing-cotton.
This cotton, on my return home, I attached to the trellis-work outside the drawing-room window, and wound across the walk and round such trees and shrubs as grew in positions convenient for my purpose.
"If these threads are broken to-morrow morning, I shall know I have a flesh-and-blood foe to encounter," I thought.
Next morning I found all the threads fastened across the walks leading round by the library and drawing-room snapped in two.