"True, but it may go far wider than that. Everything points to a plot of careful elaboration. Still, if you are satisfied----" "I am quite satisfied," replied Mr Carlyle gallantly. "I regard 'The Safe' almost as a national institution, and as such I have an implicit faith in its precautions against every kind of force or fraud." So far Mr Carlyle's attitude had been suggestive of a rock, but at this point he took out his watch, hummed a little to pass the time, consulted his watch again, and continued: "I am afraid that there were one or two papers which I overlooked. It would perhaps save me coming again to-morrow if I went back now----" "Quite so," acquiesced Carrados, with perfect gravity. "I will wait for you." For twenty minutes he sat there, drinking an occasional tiny cup of boiled coffee and to all appearance placidly enjoying the quaint atmosphere which Mr Mehmed had contrived to transplant from the shore of the Persian Gulf. At the end of that period Carlyle returned, politely effusive about the time he had kept his friend waiting but otherwise bland and unassailable. Anyone with eyes might have noticed that he carried a parcel of about the same size and dimensions as the deed-box that fitted his safe. The next day Carrados presented himself at the safe-deposit as an intending renter. The manager showed him over the vaults and strong-rooms, explaining the various precautions taken to render the guile or force of man impotent: the strength of the chilled-steel walls, the casing of electricity-resisting concrete, the stupendous isolation of the whole inner fabric on metal pillars so that the watchman, while inside the building, could walk above, below, and all round the outer walls of what was really--although it bore no actual relationship to the advertising device of the front--a monstrous safe; and, finally, the arrangement which would enable the basement to be flooded with steam within three minutes of an alarm. These details were public property. "The Safe" was a showplace and its directors held that no harm could come of displaying a strong hand. 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 to 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.