Nick was reviewing these sensational cases, as well as that then engaging him. He was wondering whether, as Chick had suggested, revenge was the motive in the present strange affair and whether Stuart Floyd might, after all, be back of the whole business.

The couch on which Nick was lying was so placed that a person reclining on it faced a mirror on one of the walls, that opposite the open door leading into the hall.

In the hall and nearly opposite this door was a large coat-and-hat stand, backed with a plate mirror. It stood at such an angle that a person lying on the couch and looking into the library mirror, which hung at an angle from the wall, could see the mirror in the hatstand, and reflected in that a portion of the hall and the front door leading to the street.

In the front door was an oval plate-glass window, with filmy lace curtains draped daintily to each side. It was plainly visible from the library by means of the double reflection under the conditions described.

The French clock on the library mantel struck the half after five.

Nick Carter heard it. It recalled to his mind the single stroke of the clock in the hall of the Carrington mansion, the half after ten the night before, a fateful moment.

Sensitive in the superlative degree, particularly to outside influences, and still thinking of the knave by whom Waldmere twice had been victimized, Nick suddenly opened his eyes.

He started slightly. He thought for an instant that he beheld a ghost, an apparition, or some mental fantasy called up by the nature of his thoughts.

For his eyes were turned toward the mirror on the wall, and in double reflection he saw the brightly lighted front hall, the massive front door, the oval window; and he beheld between the parted lace draperies the face of a man peering into the hall—the face of Stuart Floyd.

It would have caused most men to leap up from the couch, but Nick Carter never lost command of himself. He knew on the instant that this was no mental fantasy, no optical illusion.