"'SIR,--Lord TOCHTACHIE has been robbed. I overheard him last night conversing with the Hon. IAN STRUNACHAR, his eldest son, who used the following words: "Not a doubt of it. They have stolen a march----" More I could not hear at the moment. The case is of immense importance, and I trust you will lose no time in sending a competent investigator. I have, of course, concealed both my presence here and my knowledge of the theft from his lordship. "'Yours faithfully, 'DAVID MCPHIZZLE.'" "There, my boy, is the case. Will you go and help a Scotch representative peer to recover his own? Think how terrible it must be to lose the march or boundary that separates your ancestral domain from that of a neighbour whose whole course of life may be antipathetic to you. Will you go?" A wave of emotion passed over my friend's face. I could see that a struggle of no ordinary kind was raging in his breast. Finally, however, he looked at me, and his mind, I knew, was made up. In another ten minutes we had bidden adieu to his family, and were speeding northwards in the Scotch express. Over the details of the journey it is not necessary to linger. Suffice it to say that on the following morning we arrived at Tochtachie, and took up our quarters in a deserted barn situated in the very centre of the estate. From this point we pursued our investigations. Our first proceeding was to interview the local constabulary, but we found them as obtuse and as foolishly incredulous as policemen are all the world over. One of them, indeed, went so far as to hint that HOLES was "havering," which I understand to be an ancient Gaelic word signifying metaphysical talk, but a look from the great detective chilled him into silence. Day by day we worked, and not even the night gave us a rest from our self-sacrificing labours. We mapped out the whole district into square yards; we gathered the life-history of every single inhabitant on the estate; we left no clue untracked, no loophole unblocked, no single piece of evidence unexamined, no footstep unmeasured. We collected every scrap of torn letter, every crumpled telegram-form. The very heather of the moor, and the trees growing in the policies of the Castle were compelled by HOLES' marvellous inductive powers to yield to us their secrets, until after weeks of patient toil we at last judged ourselves to be in possession not only of the stolen march, but also of evidence that would bring conviction home to the guilty party. We had paused, I remember, by a heap of granite at the roadside. HOLES seemed strangely excited. "A march," I heard him muttering, "is performed by footsteps; steps are often made of stone. Can this be it? It must be! It is!" Then, with a shout of triumph, he gave orders to have the heap loaded on to a country cart, which was to follow us to the Castle.