Cross-bow in hand, I followed; and just behind me came Dame Franklin. As she moved toward the door, Old Marvin picked up his cross-bow, made sure of the poniard in his belt and followed also, mumbling the while, as best he might, the words of a Latin prayer. We came to pause amid the stillness of the vault which was like unto that of the Mountjoy tomb at Kirkwald Abbey to which one day, with my hand tightly clasping my father’s, I had paid a well remembered visit. The candle wavered and guttered in a faint draught, and the light gleamed on the wide eyes of the old dame and the trembling hands of the archer. I was standing full still with my eyes on my mother’s face. For long we stood while I could hear no sound save the beating strokes beneath my doublet. Then, suddenly, from the floor beneath or the solid wall beside us,— Tap, tap—tap—tap tap. No one spoke. The candle shook in my lady’s hand till it threatened to fall and leave us in utter darkness. Dame Franklin and the old soldier were frozen in their places. Then again: Tap tap—tap—tap tap. “Oh, Mother,” I whispered, “the passage! The secret passage! Our enemies have found it.” There was another fearsome silence. Then again—Tap tap—tap—tap tap. Then the echoes of the great vault were roused by a loud, clear call from my lady mother: “Oh, my lord! My Lord Mountjoy, is it thou?” There came a muffled voice in reply, and again we heard the tapping. [Illustration: _DAME FRANKLIN AND THE OLD SOLDIER WERE FROZEN IN THEIR PLACES_] At once she leaped toward the wall with a glad cry: “Oh, my lord, my lord, have patience but a moment. I will undo the door.” She brushed aside some old and mildewed hangings, all heavy with dust and grime, and brought to view a small iron door. Snatching from her girdle the largest key, she fitted it into the lock. Still, try as she would, she could not turn it till old Marvin came to her help. Then indeed the rusty lock gave way, the door swung slowly open, and my father, the Lord of Mountjoy, followed by half a score of knights and men-at-arms, stepped forth into the candlelight. When Lady Mountjoy at last was free from my father’s embrace, she stood with her hands on his shoulders and asked a dozen questions, demanding that he answer all at once. “Whence comest thou, my lord? Are the Scots beaten? Had’st thou news of the treachery of the Old Wolf of Carleton? How many men hast thou? Oh! I had forgot this secret passage and the door to which thou gavest me the key on our wedding day. My foolish men, and almost myself, believed thy signal was a ghostly tapping. But Dickon remembered the passage; and when I had thrice heard the signal I knew it for the knock that thou makest at my door,—the signal that means thee and none else in the world.” Meanwhile old Marvin had made fast the secret door, and we all were moving toward the stairway, my father’s arm encased in link armor thrown around the waist of the castle’s mistress.