Many men have related hideous things, not mentioned in print, which happened on the battlefields of the Great War. Some of these things have made me faint, others have convulsed me with devastating nausea, while still others have made me tremble and look behind me in the dark; yet despite the worst of them I believe I can myself relate the most hideous thing of all—the shocking, the unnatural, the unbelievable horror from the shadows.