The whole suggestion of the dark, sable figure was odd. It was exotic, and the absence of a beard greatly intensified the impression. The face, as Tristan saw it by the light of the taper, was expressionless--a physical mask.

At last Alberic broke the silence, turning his eyes full upon the man who met his gaze without flinching.

"You have--at your own risk--saved Rome and Holy Church from a calamity the whole extent of which we may not even surmise, had the Pontiff been carried away by the lawless band of Tebaldo Savello. We owe you thanks--and we shall not shirk our duty. You are a stranger. Who are you and why are you here?"

To the same questions that another had put to him on the memorable eve of his arrival, in the Piazza Navona, Tristan replied with equal frankness. His words bore the stamp of truth, and Alberic listened to a tale passing strange to Roman ears.

And, unseen by Tristan, something began to stir in the dark, unfathomable eyes of Basil, as some unknown thing stirs in deep waters, and the hidden thing therein, to him who saw, was hidden no longer. Some nameless being was looking out of these windows of the soul. One looking at him now would have shrank away, cold fear gripping his heart.

For a moment, after Tristan had finished his tale, there was silence. Alberic had risen and, seemingly unconscious of the presences in his chamber, was perambulating its narrow confines until, of a sudden, he stopped directly before Tristan.

"These penances completed, whereof you speak--do you intend returning to the land of your birth?"

A blank dismay shone in Tristan's eyes. Not having referred to the nature of the transgression, for which he was to do penance, and obtain absolution, he found it somewhat difficult to answer Alberic's question.

"This is a matter I had not considered," he replied with some hesitancy, which remained not unremarked by the Senator.

Alberic was a man of few words, and he possessed a discernment far beyond his years. At the first glance at this stranger whom fate had led across his path, he had known that here was one he might trust, could he but induce him to become his man.

He held out his hand.

"I am going to be your friend and I mean to requite the service you have done the Senator, ere the dawn of another day breaks in the sky. There is a vacancy in the Senator's guard. I appoint you captain of Castel San Angelo."

Ere Tristan could sufficiently recover from his surprise to make reply, another voice was audible, a voice, soft and insinuating--the voice of Basil, the Grand Chamberlain.

"My lord--the chain of evidence against Gamba is not completed. In fact, later developments seem to point to an intrigue of which he is but the unwitting victim--"

Alberic turned to the speaker.

"The proofs, my Lord Basil, are conclusive. Gamba is a traitor convicted of having conspired with an emissary of Ugo of Tuscany, to deliver the Archangel's Castle into his hands. He is sentenced--he shall die--as soon as we discover his abode--"

Basil's face had turned to ashen hues.

"What mean you, my lord? Gamba is awaiting sentence in the dungeon where he has been confined, ever since his trial--"

"The cage is still there," Alberic interposed sardonically. "The bird has flown."

"Escaped?" stammered the Grand Chamberlain, rising from his seat and raising his furtive eyes to those of the Senator. "Then he has confederates in our very midst--"

"We shall know more of this anon," came the laconic reply. "Will you accept the trust which the Senator of Rome offers you?" Alberic turned from the Grand Chamberlain to Tristan.

The latter found his voice at last.

"How shall I thank you, my lord!" he said, grasping the Senator's hand. "Grant me but a week, wherein to absolve the business upon which I came--and I shall prove myself worthy of the lord Alberic's trust!"

"So be it," the son of Marozia replied. "A long deferred pilgrimage to the shrines of the Archangel at Monte Gargano will take me from Rome for the space of a month or more. I should like to be assured that this keep is in the hands of one who will not fail me in the hour of need! My Lord Basil--greet the new captain of Castel San Angelo--"

Approaching almost soundlessly over the tiled floor, the Grand Chamberlain extended his hand to Tristan, offering his congratulations upon his sudden advancement.

Whatever it was that flashed in Basil's eyes, it was gone as quickly as it had come. His thin lips parted in an inscrutable smile as Tristan, with a bend of the head, acknowledged the courtesy.

For a moment, following his acceptance, Tristan was startled at his own decision. Another would have felt it to be an amazing streak of luck. Tristan was frightened, though his misgivings vanished after a time.

Owing to the lateness of the hour and the insecurity of the streets Alberic offered Tristan the hospitality of his future abode for the night and the latter gladly accepted.

After Basil had departed, he remained closeted with the Senator for the space of an hour or more. What transpired between these two remained guarded from the outer world, and it was late ere the sentinel on the ramparts saw the light in the Senator's chamber extinguished, wondering at the nature of the business which detained the lord Alberic and the tall stranger in the pilgrim's garb.