Accompanied by the observant eyes of Parkinson, Carrados gave an adventurous but not a hopeful attention to these particulars.  Submitting the problem of the tawny man to his own ingenuity, he was constantly putting before himself the question:  How shall I set about robbing this place? and he had already dismissed force as impracticable.  Nor, when it came to the consideration of fraud, did the simple but effective safeguards which Mr. Carlyle had specified seem to offer any loophole.

“As I am blind I may as well sign in the book,” he suggested, when the manager passed him a gummed slip for the purpose.  The precaution against one acquiring particulars of another client might well be deemed superfluous in his case.

But the manager did not fall into the trap.

“It is our invariable rule in all cases, sir,” he replied courteously.  “What word will you take?” Parkinson, it may be said, had been left in the hall.

“Suppose I happen to forget it?  How do we proceed?”

“In that case I am afraid that I might have to trouble you to establish your identity,” the manager explained.  “It rarely happens.”

“Then we will say ‘Conspiracy.’”

The word was written down and the book closed.

“Here is your key, sir.  If you will allow me—­your key-ring—­”

A week went by and Carrados was no nearer the absolute solution of the problem he had set himself.  He had, indeed, evolved several ways by which the contents of the safes might be reached, some simple and desperate, hanging on the razor-edge of chance to fall this way or that; others more elaborate, safer on the whole, but more liable to break down at some point of their ingenious intricacy.  And setting aside complicity on the part of the manager—­a condition that Carrados had satisfied himself did not exist—­they all depended on a relaxation of the forms by which security was assured.  Carrados continued to have several occasions to visit the safe during the week, and he “watched” with a quiet persistence that was deadly in its scope.  But from beginning to end there was no indication of slackness in the business-like methods of the place; nor during any of his visits did the “tawny man” appear in that or any other disguise.  Another week passed; Mr. Carlyle was becoming inexpressibly waggish, and Carrados himself, although he did not abate a jot of his conviction, was compelled to bend to the realities of the situation.  The manager, with the obstinacy of a conscientious man who had become obsessed with the pervading note of security, excused himself from discussing abstract methods of fraud.  Carrados was not in a position to formulate a detailed charge; he withdrew from active investigation, content to await his time.

It came, to be precise, on a certain Friday morning, seventeen days after his first visit to “The Safe.”  Returning late on the Thursday night, he was informed that a man giving the name of Draycott had called to see him.  Apparently the matter had been of some importance to the visitor for he had returned three hours later on the chance of finding Mr. Carrados in.  Disappointed in this, he had left a note.  Carrados cut open the envelope and ran a finger along the following words:—­