"If only we had an up-to-date history," sighed Henry. "Then we'd know who the sovereigns are in the Balkans. All I know are Peter, of Servia, and it seems to me that he abdicated or died; and Ferdinand, of Bulgaria; and Constantine, of Greece, who abdicated in favor of his son Alexander; and the king of Roumania—isn't his name Ferdinand, too?"
"Then there is Charles, of Austria," suggested Captain Hardy, "and the Turkish Sultan, and King Victor Emmanuel III, of Italy. But I can't think of any King James. Well, we'll drop the kings at present and go on with the cipher. That brings us to three groups of letters—twenty-six, twenty-one, twenty-four. I know that code makers frequently use arbitrary groups of letters or figures to represent given words or ideas, but I haven't the slightest notion as to whether these figures belong together or are to be read separately. And as to what they mean, we can only guess. Since they seem to be in connection with some ruler and something about a Balkan meeting-place, they might refer to troops. You don't suppose the Germans are massing forces for another drive into Roumania or that part of Russia around the Black Sea, do you?"
For a little time there was complete silence, as each member of the party struggled to remember all that he had read about the situation in the near East. But none could throw any light on the matter.
"Well, we will drop the numbers and go on," said Captain Hardy. "That brings us back to the Balaklavan rendezvous. The word rendezvous plainly indicates some kind of a meeting. A number of people are going to get together somewhere. If the place indicated were not so evidently in the Crimea, I should think that the message might mean that these German agents we've been watching are summoned to a meeting somewhere."
Again there was a long pause. "Henry," said Captain Hardy suddenly, "to whom was this message sent, and by whom?"
"It had the same call signals that have always been used. It must have been sent from the motor-car station and it is intended for the same station or stations the other messages were sent to. But we don't know yet where they are."
"What would this motor-car driver, Sanders, be sending out a message about the Balkans for?" demanded Henry. "Is he connected with the German diplomatic corps as well as with the spy activities?"
"That's exactly what I was wondering about," replied Captain Hardy. "I can make nothing of it. The only thing I can understand is the last part of the message—'nine sure.' Somebody is to meet somebody somewhere at nine o'clock sure."
"If they meet at the Balaklavan rendez—— What's that word? I can't remember, Captain Hardy," said Roy.
"Rendezvous."