The Don went over to one of the book-cases--the very section containing the shelf in which I had replaced the old law book. Taking out that particular volume, he put his hand in and pressed a spring. There was a faint click. He replaced the book and pressed against the bookcase with slow level pressure. Very slowly it seemed to give way before him; and then turning on a hinge at one side, left an open cavity through which a man could easily pass. I was about to rush in, and was quite ready, with a lamp in one hand and a revolver in the other, when the chief of the detectives laid a restraining hand on my arm as he said: "Wait a moment. If you go too fast you may obliterate some sign which would give us a clue!" The wisdom of his speech was not to be gainsaid. Instinctively I fell back; two of the trained observers drew close to the doorway, and holding their lamp in such wise as to throw light all round the opening, began an exact scrutiny. One of them knelt down and examined the flooring; the other confined his attention to roof and walls. After a silence, lasting perhaps a minute, the man kneeling stood up and said: "Not a doubt about it! There has been a violent struggle here at the doorway!" CHAPTER XLIV THE VOICE IN THE DUST One of the men produced his note book and began taking down in shorthand the rapid utterances of the chief, repeating it so as to check the accuracy as he went on: "Easy to see the marks; the floor is deep in dust, and the walls are thick with it. On floor, mark of several feet--confused in struggle, may articulate separately later on--one woman's--also trailing of long skirt. On walls marks of hands, fingers outspread, as if trying to grasp. Some of the long marks down the wall others across." The speaker here raised his lamp and held it in the opening as far as his arm would go; then he went on: "Steps wind downwards to right. Struggle seems to have stopped. Footmarks more clear."... Then the chief turned to us: "I think gentlemen, we may follow in now. The footmarks may be discriminated and identified later. We must chance destroying them, or we cannot pass in this narrow passage." Here I spoke; a thought had been surging up in my brain ever since the detective had pointed out the finger marks on the wall "down and across":