“Ah! what an unfortunate morning,” murmured Lecoq, disconsolately.  “Still I will lie in wait for him at the prefecture.”

When the door of the prison-van had been securely closed, the driver cracked his whip, and the sturdy horses started off at a brisk trot.  Lecoq had taken his seat in front, between the driver and the guard; but his mind was so engrossed with his own thoughts that he heard nothing of their conversation, which was very jovial, although frequently interrupted by the shrill voice of the Widow Chupin, who sang and yelled her imprecations alternately.

It is needless, however, to recapitulate her oaths; let us rather follow the train of Lecoq’s meditation.  By what means could he secure some clue to the murderer’s identity?  He was still convinced that the prisoner must belong to the higher ranks of society.  After all, it was not so extraordinary that he should have succeeded in feigning an appetite, that he should have concealed his distaste for a nauseous beverage, and that he should have entered the Black Maria without hesitation.  Such conduct was quite possible, indeed almost probable on the part of a man, endowed with considerable strength of will, and realizing the imminence of his peril.  But granting this, would he be equally able to hide his feelings when he was obliged to submit to the humiliating formalities that awaited him—­formalities which in certain cases can, and must, be pushed even to the verge of insult and outrage?

No; Lecoq could not believe that this would be possible.  He felt sure that the disgraceful position in which the prisoner would find himself would cause him to revolt, to lose his self-control, to utter some word that might give the desired clue.

It was not until the gloomy vehicle had turned off the Pont Neuf on to the Quai de l’Horloge that the young detective became conscious of what was transpiring around him.  Soon the van passed through an open gateway, and drew up in a small, damp courtyard.

Lecoq immediately alighted, and opened the door of the compartment in which the supposed murderer was confined, exclaiming as he did so:  “Here we are, get out.”  There was no fear of the prisoner escaping.  The iron gate had been closed, and at least a dozen agents were standing near at hand, waiting to have a look at the new arrivals.

The prisoner slowly stepped to the ground.  His expression of face remained unchanged, and each gesture evinced the perfect indifference of a man accustomed to such ordeals.

Lecoq scrutinized his demeanor as attentively as an anatomist might have watched the action of a muscle.  He noted that the prisoner seemed to experience a sensation of satisfaction directly his foot touched the pavement of the courtyard, that he drew a long breath, and then stretched and shook himself, as if to regain the elasticity of his limbs, cramped by confinement in the narrow compartment from which he had just emerged.  Then he glanced around him, and a scarcely perceptible smile played upon his lips.  One might have sworn that the place was familiar to him, that he was well acquainted with these high grim walls, these grated windows, these heavy doors—­in short, with all the sinister belongings of a prison.