Long, narrow, and low of ceiling, having on the one side a row of windows looking on to a small courtyard, and on the other a range of doors, each with a number on its central panel, thus reminding one of some corridor in a second-rate hotel, such is the Galerie d’Instruction at the Palais de Justice whereby admittance is gained into the various rooms occupied by the investigating magistrates. Even in the daytime, when it is thronged with prisoners, witnesses, and guards, it is a sad and gloomy place. But it is absolutely sinister of aspect at night-time, when deserted, and only dimly lighted by the smoky lamp of a solitary attendant, waiting for the departure of some magistrate whom business has detained later than usual. Although Lecoq was not sensitive to such influences, he made haste to reach the staircase and thus escape the echo of his footsteps, which sounded most drearily in the silence and darkness pervading the gallery. Finding an open window on the floor below, he looked out to ascertain the state of the weather. The temperature was much milder; the snow had altogether disappeared, and the pavement was almost dry. A slight haze, illumined by the ruddy glare of the street lamps, hung like a purple mantle over the city. The streets below were full of animation; vehicles were rolling rapidly to and fro, and the footways were too narrow for the bustling crowd, which, now that the labors of the day were ended, was hastening homeward or in search of pleasure. The sight drew a sigh from the young detective. “And it is in this great city,” he murmured, “in the midst of this world of people that I must discover the traces of a person I don’t even know! Is it possible to accomplish such a feat?” The feeling of despondency that had momentarily surprised him was not, however, of long duration. “Yes, it is possible,” cried an inward voice. “Besides, it must be done; your future depends upon it. Where there’s a will, there’s a way.” Ten seconds later he was in the street, more than ever inflamed with hope and courage. Unfortunately, however, man can only place organs of limited power at the disposal of his boundless desires; and Lecoq had not taken twenty steps along the streets before he became aware that if the spirit was willing, the flesh was weak. His limbs trembled, and his head whirled. Nature was asserting her rights; during the last forty-eight hours, the young detective had taken scarcely a moment’s rest, and he had, moreover, now passed an entire day without food. “Am I going to be ill?” he thought, sinking on to a bench. And he groaned inwardly on recapitulating all that he wished to do that evening.