Coquenil nodded.

“To see if the ball from that,” he looked with a shiver at the pistol, “fits in—­in that?” Again he jerked his thumb toward the wall, beyond which the body lay.

“No, that is the doctor’s business. Mine is more important.  Good night!”

“Good night,” answered Gritz and he waddled away down the corridor in his blue-silk garments, wagging his heavy head and muttering to himself:  “More important than that!  Mon Dieu!”

CHAPTER VIII

THROUGH THE WALL

Coquenil’s examination of the pistol showed that it was a weapon of good make and that only a single shot had been fired from it; also that this shot had been fired within a few hours.  Which, with the evidence of the seamstress and the dog, gave a strong probability that the instrument of the crime had been found.  If the ball in the body corresponded with balls still in the pistol, this probability would become a practical certainty.  And yet, the detective knit his brows.  Suppose it was established beyond a doubt that this pistol killed the billiard player, there still remained the question how the shooting was accomplished.  The murderer was in Number Seven, he could not and did not go into the corridor, for the corridor door was locked.  But the billiard player was in Number Six, he was shot in Number Six, and he died in Number Six.  How were these two facts to be reconciled?  The seamstress’s testimony alone might be put aside but not the dog’s testimony. The murderer certainly remained in Number Seven.

Holding this conviction, the detective entered the room of the tragedy and turned up the lights, all of them, so that he might see whatever was to be seen.  He walked back and forth examining the carpet, examining the walls, examining the furniture, but paying little heed to the body.  He went to the open window and looked out, he went to the yellow sofa and sat down, finally he shut off the lights and withdrew softly, closing the door behind him.  It was just as the commissary had said with the exception of one thing.

When he returned to Number Seven, M. Paul found that Gritz had kept his promise and sent him a pot of fragrant Turkish coffee, steaming hot, and a box of the choicest Egyptian cigarettes.  Ah, that was kind!  This was something like it!  And, piling up cushions in the sofa corner, Coquenil settled back comfortably to think and dream.  This was the time he loved best, these precious silent hours when the city slept and his mind became most active—­this was the time when chiefly he received those flashes of inspiration or intuition that had so often and so wonderfully guided him.

For half an hour or so the detective smoked continuously and sipped the powdered delight of Stamboul, his gaze moving about the room in friendly scrutiny as if he would, by patience and good nature, persuade the walls or, chairs to give up their secret.  Presently he took off his glasses and, leaning farther back against the cushions, closed his eyes in pleasant meditation.  Or was it a brief snatch of sleep?  Whichever it was, a discreet knock at the corridor door shortly ended it, and Papa Tignol entered to say that he had finished the footprint molds.