ught a moment, then he produced the pistol found in the
courtyard and examined it with extreme care, then he unlocked the corridor
door and looked out. The policeman was still on guard before Number Six.

"I shall want to go in there shortly," said the detective. The policeman
saluted wearily.

"Excuse me," ventured M. Gritz, "have you still much to do?"

"Yes," said the other dryly.

"It's nearly four and--I suppose you are used to this sort of thing, but
I'm knocked out, I--I'd like to go to bed."

"By all means, my dear sir. I shall get on all right now if--oh, they tell
me you make wonderful Turkish coffee here. Do you suppose I could have
some?"

"Of course you can. I'll send it at once."

"You'll earn my lasting gratitude."

Gritz hesitated a moment and then, with an apprehensive look in his beady
eyes, he said: "So you're going in _there?_" and he jerked his fat thumb
toward the wall separating them from Number Six.

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_.