“Did he have a visit from one of his detectives?” shot out Craig suddenly.

The clerk looked up suspiciously at us.

“No,” he replied defiantly.

“Walter—­stand by that door,” shouted Craig.  “Let no one in until they break it down.”

His blue-steel automatic gleamed a cold menace at the clerk.  A downtown office after office hours is not exactly the place to which one can get assistance quickly.  The clerk started back.

“Did he have a visit from one of his detectives?”

“Yes.”

“What was it about?”

The clerk winced.  “I don’t know,” he replied, “honest—­I don’t.”

Craig waved the gun for emphasis.  “Open the safe,” he said.

Reluctantly the clerk obeyed.  Under the point of the gun he searched every compartment and drawer of the big chrome steel strong-box which Whitney had pointed out as the safest place for the dagger on our first visit to him.  But there was absolutely no trace of it.  Had we been hoaxed and was all this risk in vain?

“Where did Mr. Whitney go?” demanded Craig, as he directed the clerk to shut the door and lock the safe again, baffled.

“If I should try to tell you,” returned the man, very much frightened, “I would be lying.  You would soon find out.  Mr. Whitney doesn’t make a confidant of me, you know.”

It was useless.  If he had the dagger, at least we knew that it was not at the office.  We had learned only one thing.  He had had a visit from one of his detectives.

As fast as the uptown trend of automobiles and surface cars during the rush hour would permit, Kennedy and I hurried in a taxicab to the Prince Edward Albert in the hope of surprising him there.

“It’s no use to inquire for him,” decided Craig as we entered the hotel.  “I still have the key to that room, 827, next to his.  We’ll ride right up in the elevator boldly and get in.”

No one said anything to us, as we let ourselves into the room next to Whitney’s.  A new lock had been placed on the door between the suites, but, aside from the additional time it took to force it, it presented no great difficulty.

“He wouldn’t leave the dagger here, of course,” remarked Kennedy, as at last we stepped into Whitney’s suite.  “But we may as well satisfy ourselves.  Hello—­what’s this?”

The room was all upset, as though some one had already gone through it.  For a moment I thought we had been forestalled.

“Packed a grip hastily,” Craig remarked, pointing to the marks on the bedspread where it had rested while he must literally have thrown things into it.

We made a hasty search ourselves, but we knew it was hopeless.  Two things we had learned.  Whitney had had a visit from his detectives, and he had gone away hurriedly.  An anonymous telephone message had been sent to Kennedy.  Had it been for the purpose of throwing us off the track?

The room telephone rang.  Quickly Craig jumped to it and took down the receiver.