One or two starched and ordinary-looking mechanics stood beside and behind me,--stragglers, who, like ourselves, had been too late in obtaining entrance. But a glance at their faces satisfied me, though I could hardly say why, that none of these was the person who had spoken to me. Their countenances seemed all composed to attention to the sermon, and not one of them returned any glance of intelligence to the inquisitive and startled look with which I surveyed them. A massive round pillar, which was close behind us, might have concealed the speaker the instant he uttered his mysterious caution; but wherefore it was given in such a place, or to what species of danger it directed my attention, or by whom the warning was uttered, were points on which my imagination lost itself in conjecture. It would, however, I concluded, be repeated, and I resolved to keep my countenance turned towards the clergyman, that the whisperer might be tempted to renew his communication under the idea that the first had passed unobserved. My plan succeeded. I had not resumed the appearance of attention to the preacher for five minutes, when the same voice whispered, "Listen, but do not look back." I kept my face in the same direction. "You are in danger in this place," the voice proceeded; "so am I--meet me to-night on the Brigg, at twelve preceesely--keep at home till the gloaming, and avoid observation." Here the voice ceased, and I instantly turned my head. But the speaker had, with still greater promptitude, glided behind the pillar, and escaped my observation. I was determined to catch a sight of him, if possible, and extricating myself from the outer circle of hearers, I also stepped behind the column. All there was empty; and I could only see a figure wrapped in a mantle, whether a Lowland cloak, or Highland plaid, I could not distinguish, which traversed, like a phantom, the dreary vacuity of vaults which I have described.