The Aglae safes, turned out very sparingly by Creusot, are the last word in their line. He knew them well. There was one in the Commissioner's office at the Yard. They are pretty to look at. No cumbersome, easily detected combination lock here. A little slit, looking as innocent as a slot-machine, faced him, but any key, whether of another Aglae or not, which was not the right one would set a powerful alarum ringing against the light metal of the outer door which no cushion could deaden, and it would ring until the right key was inserted, if need be for thirty-five days. If a burglar, caring nothing for keys, tried his usual tactics of cutting, he would find an outer case which let itself be opened with ease, and out would stream a volume of gas calculated to render anyone unconscious who stood near it, even though the windows were open. Some Aglae had an alternative plan by which a revolver emptied its six cartridges in the direction where the first cut was made. Altogether, a slight acquaintance with an Aglae was distinctly advisable for any up-to-date cracksman if he wanted a chance to show his talents elsewhere. Pointer whistled softly. There was only one man in Europe who could help him. In Barcelona, at the foot of Tibidabo, lives a Catalan, a Senor Foch, who works in a simple little shop with his son for the police of seven countries; and lucky it was for the police that honesty had been the motto of the two men, for there is nothing that can be done to lock or key that they cannot do. Only a Foch could copy the key of this safe, supposing Pointer could lay his hands on it for a moment. The Catalans worked only on their own terms. Measurements, weight, and impressions had to be taken, according to their strict rules, or they would refuse the job. He replaced everything as he had found it, took off the silencers from the various alarums, and proceeded with his room to room inspection. In Major Vaughan's flat he found some things which interested him greatly. He even went so far as to take a tracing of some boots and shoes he found up there, and very familiar the outline would have looked to Watts, too, had he seen it. It was close on six o'clock when he finished, and the only results to the eye for a very fatiguing day was a little cardboard box of a kind which had contained stationery, a tiny oval box retrieved from a dusty corner of the attic, and a little yellow pill-box, marked “Mrs. Erskine, 14 Ave. de Paris, Biarritz,” that had come from a deep pocket of an old travelling bag. Yet with these, and his tracings, and his other discoveries, the Chief Inspector felt more than satisfied. Next morning he took his leave of Mrs. Erskine, and acknowledged that she had been right in thinking that the papers which he had looked over contained no clue. “I'm quite sure that the criminal is that man you let go, Carter!”