Although she had not gone so far as a regiment of soldiers, that precaution had been taken--and precautions, moreover, which had been found to be adequate, over and over again, on previous occasions--was sufficiently plain. The duchess had travelled in a reserved saloon carriage by the five minutes past four train from Windsor to Paddington. She had been accompanied by two servants, her maid, and a man-servant named Stephen Eversleigh. Eversleigh was one of a family of servants the members of which had been in the employment of the Dukes of Datchet for generations. It was he who was in charge of the diamonds. They were in a leather despatch-box. The duchess placed them in it with her own hand, locked the box, and retained the key in her own possession. Eversleigh carried the box from the duchess's apartment in the Castle to the carriage which conveyed her to the railway station. He placed it on the seat in front of her. He himself sat outside with the maid. When the carriage reached the station he carried it to the duchess's saloon. The duchess was the sole occupant of the saloon. She travelled with the despatch-box in front of her all the way to London. The duke met her at Paddington. Eversleigh again placed the box on the front seat of the carriage, the duke and duchess, sitting side by side, having it in full view as the brougham passed through the London streets. The diamonds, when not in actual use, were always kept, for safe custody, at Bartlett's Bank. The confidential agent of the bank was awaiting their arrival when the brougham reached the ducal mansion in Grosvenor Square. The despatch-box was taken straight to him, and, more for form's sake than anything else, was opened by the duchess in his presence, so that he might see that it really did contain the diamonds before he gave the usual receipt. It was as well for the bank's sake that on that occasion the form was observed. When the box was opened, it was empty! There was nothing of any sort to show that the diamonds had ever been in it--they had vanished into air! When he had reached this point Mr. Paxton put the paper down. He laughed. "That's a teaser. The position seems to promise a pleasing problem for one of those masters of the art of detection who have been cutting such antics lately in popular fiction. If I were appointed to ferret out the mystery, I fancy that I should begin by wanting to know a few things about her Grace the Duchess. I wonder what happened to that despatch-box while she and it were tête-à-tête? It is to be hoped that