"Finally, rousing myself from a lethargy of horror, I got on my feet again and began following the footprints. Who the murderer was, I could not even faintly guess, nor could I try to explain the absence of the servants. I vaguely felt that I ought to go up to Marsh's attic quarters, but before I had fully formulated the idea I saw that the bloody trail was indeed taking me there. Was he himself the murderer? Had he gone mad under the strain of the morbid situation and suddenly run amok?