The Professor, who was comfortably seated in Quest’s favourite easy-chair, glanced at his watch and shook his head.

“I am afraid, my friend,” he said, “that Craig’s nerve has failed him.  A voluntary surrender was perhaps too much to hope for.”

Quest smoked for a moment in silence.

“Can’t understand those fellows letting him give them the slip,” he muttered.  “He ought to have been under close surveillance from the moment he set foot in New York.  What’s that?” he added, turning to the door.

His servant entered, bearing a note.

“This was left a few minutes ago, sir,” he announced, “by a messenger boy.  There was no answer required.”

The man retired and Quest unfolded the sheet of paper.  His expression suddenly changed.

“Listen!” he exclaimed.

    To Sanford Quest.

    Gather your people in Professor Ashleigh’s library at ten
    o’clock to-night.  I will be there and tell you my whole story.

    JOHN CRAIG.

The Professor sat for a moment speechless.

“Then he meant it, after all!” he exclaimed at last.

“Seems like it,” Quest admitted.  “I’ll just telephone to French.”

The Professor rose to his feet, knocked the ash from his cigar, struggled into his coat, and took up his hat.  Then he waited until Quest had completed his conversation.  The latter’s face had grown grave and puzzled.  It was obvious that he was receiving information of some importance.  He put down the instrument at last with a curt word of farewell.

“Let me send a couple of men up with you, Professor,” he begged.  “You don’t want to run any risk of having Craig there before we arrive.”

The Professor smiled.

“My friend,” he said, “it is seldom in my life that I have had to have recourse to physical violence, but I flatter myself that there is no man who would do me any harm.  We will meet, then, at my house.  You will bring the young ladies?”

“Sure!” Quest replied.  “I am just sending word up to them now.”

The Professor moved towards the door.

“If only this may prove to be the end!” he sighed.

* * * * *

Quest spent the next hour or so in restless deliberations.  There were still many things which puzzled him.  At about a quarter past nine Lenora and Laura arrived, dressed for their expedition.  Quest threw open the window and looked out across the city.  A yellowish haze which, accompanied by a sulphurous heat, had been brooding over the city all day long, had suddenly increased in density.  The air was stifling.

“I’m afraid we are in for a bad thunderstorm, girls,” Quest remarked.

Laura laughed.

“Who cares?  The automobile’s there, Mr. Quest.”

“Let’s go, then,” he replied.

They descended into the street and drove to the Professor’s house in silence.  Even Laura was feeling the strain of these last hours of anxiety.  On the way they picked up French and a plain-clothes man, and the whole party arrived at their destination just as the storm broke.  The Professor met them in the hall.  He, too, seemed to have lost to some extent his customary equanimity.