“The explanation is a simple one,” said Nick. “Two strangers got by Perkins by using these two cards.”

“But Ringold would not have given his cards to others. He is above such discourtesy as that,” Carrington warmly protested.

“Undoubtedly,” Nick agreed. “It is safe to assume, then, that the cards were obtained from him by covert means, also that a subterfuge of some kind was employed to prevent him and his wife from coming here to-night, or even communicating with you.

“But that smacks of knavery, Mr. Carter, if not crime itself,” said Mr. Carrington apprehensively.

“I now am sure of knavery of some kind,” Nick replied. “Whether it is so serious as to come under the head of crime remains to be learned.”

“Dear me, this is shocking.”

“I now will tell you what I saw about half past ten this evening,” Nick added. “I want you to say nothing about it, pending my further investigations.”

Both of his companions pledged themselves to secrecy, and Nick then briefly told them of his earlier observations, much to the amazement of Mr. Carrington and the increasing anxiety of Mollie Waldmere.

“Don’t let my disclosures add to your alarm,” said Nick, observing her paleness. “The circumstances admit of only one interpretation.”

“What is your opinion?” Mollie questioned.