Zabern smiled cynically.
"The duke has come to count it no great prize to have but a moiety of the throne, and to be mated withal to a little lady who will take no bidding from him, and therein small blame to her. The princess hath ever been cold to the match, and therefore the duke, doubtful of her affection, has begun to play a double part, or in other words, to intrigue with Russia. 'Dispense with the princess, and reign alone under the suzerainty of the Czar'—that is his secret ambition. What other conclusion can I come to, when I see him tampering with the Czernovese army? On frivolous pretexts he has removed Polish officers from their command, replacing them by such Muscovites as have at heart the interests of the Czar rather than those of the princess. Moreover, we have certain proof that our cabinet contains a member who reveals to Russia our secret counsels. You know the cabinet well, Trevisa; tell me whom to suspect. Radzivil?—absurd! Ravenna? What hath a Roman cardinal to gain by inviting the head of the Greek Church to take possession of Czernova? Dorislas? Then let me fall on my sword's point, so certain am I of never again finding faith among men, if he be traitor. Mosco, the Greek Arch-pastor? Hum! his zeal on behalf of the princess has perhaps diminished somewhat since her conversion to Catholicism, but he is more dullard than villain. Polonaski the Justiciary? I'll mention no more. When we would discover the author of a crime, we naturally fix our suspicions upon the man who has most to gain by the deed. Judged by this test the duke, and the duke alone, is the traitor. Delendus est Bora! Czernova will never be sound till he be gone."
There was no reply from Trevisa, who seemed to be lost in deep thought. Then suddenly his eyes lightened as with some new and surprising idea.
"Marshal," said he emphatically, "you shall have a translation of that letter in the morning."
It took a good deal to surprise the marshal; nevertheless on the present occasion he was quite confounded.
"How? What?" he cried. "You claim to have discovered the key to the cipher, when but a minute ago you professed ignorance of the very language in which the letter is written?"
"The language is Greek," murmured Trevisa, almost breathless at his discovery, and talking more to himself than to his companions. "Yes, yes; I comprehend it all now. The most ingenious cipher ever devised. Nothing but an accident could have revealed the key. You are quite correct, marshal, in your estimate of the duke's character. He is a traitor, and that letter will prove it. I will work at it to-night, and to-morrow morning you shall have the result."
"Good!" replied Zabern, mystified, as was Paul likewise, by the suddenness with which Trevisa had arrived at the solution of a problem that during the past month had baffled his wit.
The shades of twilight were falling as the trio drew near to "Sobieski's Rest," an inn so called because the greatest of the Polish kings had once passed a night there. It was a spacious and picturesque hostelry, composed of a mixture of stone and timber, and shaded by overhanging birch-trees.
Outside the building, and holding two horses by the bridle, stood the trooper Nikita, Zabern's orderly, who had been sent on ahead to await the arrival of the marshal.