Now there was a certain fact at the bottom of this belief of Mrs. Hopkins; and as it world be a very small thing to make a mystery of so simple a matter, the reader shall have the whole benefit of knowing all there is in it,—­not quite yet, however, of knowing all that came of it.  It was not the mirror trick, of course, which Mrs. Felix Lorraine and other dangerous historical personages have so long made use of.  It was nothing but this:  Mr. Byles Gridley wore a pair of formidable spectacles with large round glasses.  He had often noticed the reflection of objects behind him when they caught their images at certain angles, and had got the habit of very often looking at the reflecting surface of one or the other of the glasses, when he seemed to be looking through them.  It put a singular power into his possession, which might possibly hereafter lead to something more significant than the mystification of the Widow Hopkins.

A short time before Myrtle Hazard’s disappearance, Mr. Byles Gridley had occasion to call again at the office of Penhallow and Bradshaw on some small matter of business of his own.  There were papers to look over, and he put on his great round-glassed spectacles.  He and Mr. Penhallow sat down at the table, and Mr. Bradshaw was at a desk behind them.  After sitting for a while, Mr. Penhallow seemed to remember something he had meant to attend to, for he said all at once:  “Excuse me, Mr. Gridley.  Mr. Bradshaw, if you are not busy, I wish you would look over this bundle of papers.  They look like old receipted bills and memoranda of no particular use; but they came from the garret of the Withers place, and might possibly have something that would be of value.  Look them over, will you, and see whether there is anything there worth saving.”

The young man took the papers, and Mr. Penhallow sat down again at the table with Mr. Byles Gridley.

This last-named gentleman felt just then a strong impulse to observe the operations of Murray Bradshaw.  He could not have given any very good reason for it, any more than any of us can for half of what we do.

“I should like to examine that conveyance we were speaking of once more,” said he.  “Please to look at this one in the mean time, will you, Mr. Penhallow?”

Master Gridley held the document up before him.  He did not seem to find it quite legible, and adjusted his spectacles carefully, until they were just as he wanted them.  When he had got them to suit himself, sitting there with his back to Murray Bradshaw, he could see him and all his movements, the desk at which he was standing, and the books in the shelves before him,—­all this time appearing as if he were intent upon his own reading.