right before me, a quarter of a mile off, its turrets and gables vividly illuminated in the glare.  And when that glare passed, as quickly as it had come, and the heavy blackness fell again, there was a gleam of light, coming from some window or other, and I made for that, going swiftly and silently over the intervening space, not without a fear that if anybody should chance to be on the watch another lightning flash might reveal my advancing figure.

But there had been no more lightning by the time I reached the plateau on which Hathercleugh was built; then, however, came a flash that was more blinding than the last, followed by an immediate crash of thunder right overhead.  In that flash I saw that I was now close to the exact spot I wanted—­the ancient part of the house.  I saw, too, that between where I stood and the actual walls there was no cover of shrubbery or coppice or spinny—­there was nothing but a closely cropped lawn to cross.  And in the darkness I crossed it, there and then, hastening forward with outstretched hands which presently came against the masonry.  In the same moment came the rain in torrents.  In the same moment, too, came something else that damped my spirits more than any rains, however fierce and heavy, could damp my skin—­the sense of my own utter helplessness.  There I was—­having acted on impulse—­at the foot of a mass of grey stone which had once been impregnable, and was still formidable!  I neither knew how to get in, nor how to look in, if that had been possible; and I now saw that in coming at all I ought to have come accompanied by a squad of police with authority to search the whole place, from end to end and top to bottom.  And I reflected, with a grim sense of the irony of it, that to do that would have been a fine long job for a dozen men—­what, then, was it that I had undertaken single-handed?

It was at this moment, as I clung against the wall, sheltering myself as well as I could from the pouring rain, that I heard through its steady beating an equally steady throb as of some sort of machine.  It was a very subdued, scarcely apparent sound, but it was there—­it was unmistakable.  And suddenly—­though in those days we were only just becoming familiar with them—­I knew what it was—­the engine of some sort of automobile; but not in action; the sound came from the boilers or condensers, or whatever the things were called which they used in the steam-driven cars.  And it was near by—­near at my right hand, farther along the line of the wall beneath which I was cowering.  There was something to set all my curiosity aflame!—­what should an automobile be doing there, at that hour—­for it was now nearing well on to midnight—­and in such close proximity to a half-ruinous place like that?  And now, caring no more for the rain than if it had been a springtide shower, I slowly began to creep along the wall in the direction of the sound.