Let it be distinctly borne in mind that the paper was in a despatch-box, locked. The despatch-box was in a safe, locked. The safe was in the Prince’s private bureau, where none but the privileged were allowed to enter, and the door of which was also locked. Now, then, let it be still further remembered that the keys necessary to open the door of the safe and the despatch-box were kept in a safe in the Prince’s bedroom, and the key of that safe was one of a number which every night were given into the custody of Vladimir Nicolayeff, the Clerk of the Keys.

There was another point which had to be very closely considered. It was this: the person who stole the document must have known it was there. He could not have known it was there if he had not occupied a position which enabled him to learn a good deal of what was going on; but as it could not be supposed for a moment that a Minister like the Prince would have lightly made a confidant of an inferior and irresponsible person, it was difficult to believe that the crime was the work of one individual; and here again Danevitch had to build up a theory, which he did as follows:

A was in possession of a secret that a draft treaty was being conveyed from Bulgaria to Russia, and would reach the Prince at a certain hour on a certain day, and for political or mercenary motives imparted the information to B, who, probably for political motives only, wished to make it known to the Government of the country against which the treaty was framed. B had to fall back upon C to procure the keys, without which the documents could not be carried off.

Here at once a conspiracy was suggested, and, a conspiracy admitted, it was impossible to dismiss the courier and Vladimir Nicolayeff from it. These two men, of course, represented extremes of position. The courier, whose name was Boruff, was a trusted and confidential Government officer of good birth and high social position. Nicolayeff, on the other hand, was a porter—a trusted servant, it was true, but a servant of humble origin and low rank. His services, if they had been given and used, must have been bought; that is, he had been corrupted, tempted from his allegiance by money. Next, the third or middle person had to be considered. What position did he occupy? It was not easy to answer that beyond saying it was obviously someone very close to the Prince.

Having arranged these various points, and set them forth in their order, he felt satisfied that his theory was a feasible one, and, if acted upon, was more likely to yield results than the search-for-the-needle-in-the-bottle-of-hay process of stopping people at the frontiers. At any rate, while that process was being carried out, Danevitch proceeded on his own lines, and his first step was directed to learning some particulars about Boruff.

In age the courier verged on forty. He had been in the Government service for fifteen years. Every confidence was reposed in him, and he was greatly respected. He had been engaged on courier duty for something like four years, and had made many journeys between Turkey and Russia. Formerly he had been a confidential clerk at the Russian Consulate at Smyrna.

He was a married man, and had four children, but lived apart from his family. There had been serious disagreements between him and his wife, owing, so it was stated, to his infatuation for another lady, which had led to all sorts of complications, difficulties, and domestic jars. These, of course, were purely family matters, and had not affected his Government position, as it was considered there were faults on both sides. Boruff was not well off. Such officials are poorly paid in Russia; and as he was forced to keep up two establishments, and moreover was extravagant, his resources were severely taxed.

So much did Danevitch learn of Boruff. Not much, if anything at all, to suggest a probability that Boruff had any guilty knowledge. He was a poor man; that was the worst that could be said about him. But poverty lays a man open to many temptations. Starving virtue is sorely tested when gold is jingled in its ears. It is so easy to be honest when one wants for nothing.

Such were Danevitch’s reflections, and he put Boruff in his note-book, as he says, for future use if necessary. He thought it was just possible that ultimately the courier would prove one of the pieces necessary to complete the puzzle.

He next turned his attention to Vladimir Nicolayeff, a man of a totally different stamp. He was an old man—well, that is, he was close on sixty. He had been in the army, and had seen service in his youth, but, having been severely wounded, was discharged, and ultimately got employment under the Government. He had served at the Foreign Office a great many years. His position, though humble, was an important one. In his lodge in the entrance-hall all the keys not in use were kept. He also received messages and parcels, answered questions of inquirers, and pointed out the way to the different departments.