"I do. It contains Paul, fourth Baron Lashmore, son of Mirza, the Polish Jewess!" Lord Lashmore reseated himself in the big armchair, staring at the speaker, aghast. "I thought no other in the world knew that!" he said, hollowly. "Your studies have been extensive indeed. For three years--three whole years from the night of my twenty-first birthday--the horror hung over me, Dr. Cairn. It ultimately brought my grandfather to the madhouse, but my father was of sterner stuff, and so, it seems, was I. After those three years of horror I threw off the memories of Paul Dhoon, the third baron--" "It was on the night of your twenty-first birthday that you were admitted to the subterranean room?" "You know so much, Dr. Cairn, that you may as well know all." Lashmore's face was twitching. "But you are about to hear what no man has ever heard from the lips of one of my family before." He stood up again, restlessly. "Nearly thirty-five years have elapsed," he resumed, "since that December night; but my very soul trembles now, when I recall it! There was a big house-party at Dhoon, but I had been prepared, for some weeks, by my father, for the ordeal that awaited me. Our family mystery is historical, and there were many fearful glances bestowed upon me, when, at midnight, my father took me aside from the company and led me to the old library. By God! Dr. Cairn--fearful as these reminiscences are, it is a relief to relate them--to _someone_!" A sort of suppressed excitement was upon Lashmore, but his voice remained low and hollow. "He asked me," he continued, "the traditional question: if I had prayed for strength. God knows I had! Then, his stern face very pale, he locked the library door, and from a closet concealed beside the ancient fireplace--a closet which, hitherto, I had not known to exist--he took out a bulky key of antique workmanship. Together we set to work to remove all the volumes from one of the bookshelves. "Even when the shelves were empty, it called for our united efforts to move the heavy piece of furniture; but we accomplished the task ultimately, making visible a considerable expanse of panelling. Nearly forty years had elapsed since that case had been removed, and the carvings which it concealed were coated with all the dust which had accumulated there since the night of my father's coming of age. "A device upon the top of the centre panel represented the arms of the family; the helm which formed part of the device projected like a knob. My father grasped it, turned it, and threw his weight against the seemingly solid wall. It yielded, swinging inward upon concealed hinges, and a damp, earthy smell came out into the library. Taking up a lamp, which he had in readiness, my father entered the cavity, beckoning me to follow.