"If Dollon had been alive," reflected Fandor, "it is evident that, once on the roofs, he had a choice of three ways to escape: he could do what I have just done, but the other way about; he could break a skylight, jump into a garret, and lie hidden under the tiles, awaiting the propitious moment when he could gain the corridors below and, mingling with the crowd, slip unobserved into the street; or, he could hide among the roofs, and stay there; or, he could search for an opening--one of those air holes which put the cellars and drains in communication with the exterior.... But I have come to the conclusion that Dollon is dead! Then his corpse could only remain up here; or, it has been put down into some place where nobody goes. The garrets of the Palais are so incessantly visited by the clerks and registrars that no corpse could remain undiscovered in any of them. Therefore, either Jacques Dollon's corpse is somewhere on the roofs of the Palais, or there is some sort of communication between the roofs and the drains--it is obvious!" Evidently the next step was to search every hole and corner of these same roofs. Armed with revolver and lantern, Fandor started on his tour of investigation; but prudently, for he was now almost certain that there were a number of accomplices involved in this Dollon affair. To go carefully over the enormous roof of the Palais de Justice was no light task! One has only to consider the immensity of this monumental pile, its complicated architecture, the numberless little courts enclosed within its vast confines, to understand the difficulties with which our intrepid journalist had to contend. But Jerome Fandor was not the man to be discouraged in the face of difficulties: he was determined to brave them--conquer them! He examined, minutely, the entire roofing of the Palais; he did not leave a corner or a morsel of shadow unexplored; there was not a gutter which he had not searched from end to end. When, after two hours of strenuous exertion, he returned to his starting-point, the chimney of Marie Antoinette, he was fain to confess that if Jacques Dollon had mounted to the roof of the Palais de Justice he certainly had not remained there. Fandor unfolded his plan once more. It fluttered in the night breeze, as he carefully numbered all the chimneys opening on to this roof; then, one by one, he identified them with the real chimneys before his eyes. He exclaimed joyfully: "There, now! It's just what I suspected!" He had discovered there was one chimney not down on the plan: "Whither did it lead?" At all costs he must find out--make sure. He hastened to this extra chimney. Its orifice was large enough to allow of the passage of a man; also, here again, stones had been recently loosened, and a rope had rubbed against them: "What the deuce is this chimney?" thought Fandor. "Another mystery! This chimney is not a chimney; there is not a trace of soot on it, even old soot!" After a moment's reflection, he added: