"I have known of it for many years," Mildred said, "and never spoken of it to any one. My Sister Mary discovered it: you have heard, I think, that she was one of us in early days: but she died young. After we took possession of this building, Mary, who was lively and active, used to go about, above ground and under it, exploring, as she called it. One day she came upon a secret door below, that disclosed a dark, narrow passage: she penetrated some distance into it, but did not cate to go on alone. At night, when the rest of the ladies had retired, she and I stayed up together--just as you and I have stayed up to-night, my dear, for it was in this very parlour--and she got me to go and explore it with her. We took a lantern to light our steps, and went. The passage was narrow, as I have said, and apparently built in a long straight line, without turnings, angles, or outlets. Not to fatigue you, I will shortly say, that after going a very long way, as it seemed to us, poor timid creatures that we were, we passed through another door, and found ourselves in a pillared place that looked not unlike cloisters, and at length made it out to be vaults under the Friar's Keep." "What a strange thing!" exclaimed Mary Ursula, speaking into the instrument she had recently made the good Sister a present of--a small ear-trumpet, for they were talking almost in a whisper. "Not so strange when you remember what the place was originally," dissented Sister Mildred. "Tradition says, you know, that these old religions buildings abounded in secret passages. I did not speak of the discovery, and enjoined silence on Mary; the Sisters might have been uncomfortable; and it was not a nice thing, you see, to let the public know there was a secret passage into our abode." "Did you never enter it again?" "Yes, once. Mary would go; and of course I could not let her go alone. It was not long before the illness came on that terminated in her death. Ah, my dear, we were young then, and such an expedition bore for us a kind of pleasurable romance." Mary Ursula sat in thought. "It strikes me as not being a pleasant idea," she said--"the knowledge that we may be invaded at any hour by some ill-disposed or curious straggler, who chooses to frequent the Friar's Keep." "Not a bit of it, my dear," said Sister Mildred, briskly. "Don't fear. We can go to the Keep at will, but the Keep cannot come to us. The two doors are firmly locked, and I hold the keys." "I should like to see this passage!" exclaimed Mary Ursula. "Are you--dear Sister Mildred, do you think you are well enough to show it to me?"