The lift in the hall behind them swirled up again and the gate clashed.  The second man walked leisurely out and sauntered away without a backward glance.

“He has gone in the opposite direction,” exclaimed Mr. Carlyle, rather blankly.  “It isn’t the ‘lame goat’ nor the ‘follow-me-on,’ nor even the homely but efficacious sand-bag.”

“What colour were his eyes?” asked Carrados.

“Upon my word, I never noticed,” admitted the other.

“Parkinson would have noticed,” was the severe comment.

“I am not Parkinson,” retorted Mr. Carlyle, with asperity, “and, strictly as one dear friend to another, Max, permit me to add, that while cherishing an unbounded admiration for your remarkable gifts, I have the strongest suspicion that the whole incident is a ridiculous mare’s nest, bred in the fantastic imagination of an enthusiastic criminologist.”

Mr. Carrados received this outburst with the utmost benignity.  “Come and have a coffee, Louis,” he suggested.  “Mehmed’s is only a street away.”

Mehmed proved to be a cosmopolitan gentleman from Mocha whose shop resembled a house from the outside and an Oriental divan when one was within.  A turbaned Arab placed cigarettes and cups of coffee spiced with saffron before the customers, gave salaam and withdrew.

“You know, my dear chap,” continued Mr. Carlyle, sipping his black coffee and wondering privately whether it was really very good or very bad, “speaking quite seriously, the one fishy detail—­our ginger friend’s watching for the other to leave—­may be open to a dozen very innocent explanations.”

“So innocent that to-morrow I intend taking a safe myself.”

“You think that everything is all right?”

“On the contrary, I am convinced that something is very wrong.”

“Then why—?”

“I shall keep nothing there, but it will give me the entree.  I should advise you, Louis, in the first place to empty your safe with all possible speed, and in the second to leave your business card on the manager.”

Mr. Carlyle pushed his cup away, convinced now that the coffee was really very bad.

“But, my dear Max, the place—­’The Safe’—­is impregnable!”

“When I was in the States, three years ago, the head porter at one hotel took pains to impress on me that the building was absolutely fireproof.  I at once had my things taken off to another hotel.  Two weeks later the first place was burnt out.  It was fireproof, I believe, but of course the furniture and the fittings were not and the walls gave way.”

“Very ingenious,” admitted Mr. Carlyle, “but why did you really go?  You know you can’t humbug me with your superhuman sixth sense, my friend.”

Carrados smiled pleasantly, thereby encouraging the watchful attendant to draw near and replenish their tiny cups.

“Perhaps,” replied the blind man, “because so many careless people were satisfied that it was fireproof.”