Was he guilty of a secret love affair, as Chick had suggested, and had he gone to indulge in a clandestine flirtation, intending to return within a reasonable time, only to be inadvertently detained until this late hour?

Nick was not inclined to believe anything of that kind, as a matter of fact. He had a very high opinion of the titled young Englishman, who had been loyal enough to his love for a beautiful chorus girl to make her his wife, in spite of the opposition of his choleric old father, the Earl of Eggleston, and the consequent estrangement from home and family and native land, he having for the two years since his marriage been engaged in Western mining projects, occupying a fine residence in Riverside Drive.

In view of all of these facts, of which Nick was thoroughly informed, he did not believe that Waldmere was guilty of a clandestine love affair. He decided that he would not immediately disclose what he had seen, however, and that he first would look into the matter superficially and make sure he was right on certain points.

For Nick did not know positively, of course, that it was Mollie Waldmere whom he had seen ascending the front stairs at precisely half past ten. There was a possibility of its having been the other—the unknown personification of Night.

“It really is extraordinary, most extraordinary,” Mr. Carrington remarked, when the detective did not reply for a moment to the anxious woman. “I cannot account for it.”

“I don’t think there is any cause for alarm,” said Nick. “Have you made sure, Mrs. Waldmere, that your husband is not in the house?”

“Dear me, yes!” exclaimed Mollie, gazing at him. “I have searched everywhere in the crowd. It is nearly two hours since we unmasked. Archie was to have gone in with me for refreshments, but I have waited and searched in vain. I know, Mr. Carter, that something has happened to him. He would never desert me in this way. Besides, he did a most extraordinary thing earlier in the evening.”

“What was that?” Nick inquired. “Sit down, Mrs. Waldmere, and tell me. I will look into the matter.”

Mr. Carrington had closed the door of his private library, and all three then sat down to continue the discussion.

“He sent me a note about half past ten, Mr. Carter, asking me to join him in the west-front chamber, and saying that he wanted me. Here it is, merely these penciled lines on a scrap of paper. I thrust it into my waist, not wanting to drop it on the floor.”