My watch was from three to four-thirty. I was prowling around the halls, peering into each room as I passed, when above the night noises and the snoring of the Colonel I thought I heard an ominous creaking. On tiptoe I went down the hall, past the stairwell that went down into sinister blackness, and fetched up some yards thereafter before a gaping square hole in the wall of the passageway. What the devil...! I turned the beam of my electric torch into it. It was another staircase, narrow and steep, which I had not known existed. Without hesitation I started down its creaky old treads. The air was musty and smelled of a thousand generations of mice. More through my skin than my ears I got the impression that someone was descending these secret stairs in advance of me. I drew out one of my guns, with a childlike thrilling of my pulse, and muffling the torch's light with the fingers of my left hand so that only a thin streak or two of brightness preceded my searching feet, I went down. The square door at the bottom was standing wide. Slipping through it, with the torch now dark, I stood still and listened. * * * * * The moon's rays patterned the cold floor under the windows, and across one of them I thought I saw a shadow glide. I swiveled my head quickly. Perhaps I had been mistaken. There was nothing there. The end of the room in which was cradled the massive black fireplace lay in impenetrable gloom. Watching this, I felt the skin of my neck creep and the hair bristle.... _Something_ had moved in that murk, I could swear it. Something bigger and more ponderous than a body. I could not pin down the exact analogy I groped for: it was as if ... as if the wall had suddenly advanced toward me, and then sunk back again. I husked through a dry throat. This would not do. Despite the usurpers without, I had to risk a light. I shot the beam of the torch across the wall from corner to corner. Nothing moved. I went to the cold fireplace--feeling the eyes of a multitude of ghosts upon me as I moved--and ran the flash over it. I even knelt and peered up the gut of the chimney. Nothing. I found myself shuddering. One more sweep of the torch around the vault of the hall, and then I ran (I admit it freely) for the secret door. Pulling it to behind me, I raced up the narrow steps and with pounding heart slammed the upper one also. I saw then that it was a swinging panel, that looked much like any one of the other panels in the hall. This secret must be a relic of the bad old days, when Exeter Castle was young and the nobility was riddled with treachery, intrigue, and evil. After two minutes of cogitation, I went and aroused Colonel Bedford. He listened to my tale in silence. Then, "This might be serious," he said. "Let's wake the others."