was the very thing for him to stand on, a
sofa just in place. So, _if_ Martinez bored these holes, he stood on this
sofa to do it, and, in that case, the marks of his heels must have remained
on the delicate satin. And here they are."

"Yes, here they are, nails and all," admitted Tignol admiringly. "I'm an
old fool, but--but----"

"Well?"

"Tell me _why Martinez did it_."

Coquenil's face darkened. "Ah, that's the question. We'll know that when we
talk to the woman."

The old man leaned forward eagerly: "_Why do you think the woman helped
him?_"

"_Somebody_ helped him or the chips would still be there, _somebody_ held
back those hangings while he worked the auger, and somebody carried the
auger away."

Tignol pondered this, a moment, then, his face brightening: "Hah! I see!
The sofa hangings were held back when the shot came, then they fell into
place and covered the holes?"

"That's it," replied the detective absently.

"And the man in Number Seven, the murderer, lifted that picture from its
nail before shooting and then put it back on the nail after shooting?"

"Yes, yes," agreed M. Paul. Already he was far away on a new line of
thought, while the other was still grappling with his first surprise.

"Then this murderer must have _known_ that the billiard player was going to
bore these holes," went on Papa Tignol half to himself. "He must have been
waiting in Number Seven, he must have stood there with his pistol ready
while the holes were coming through, he must have let Martinez finish one
hole and then bore the other, he must have kept Number Seven dark so they
couldn't see him----"

"A good point, that," approved Coquenil, paying attention. "He certainly
kept Number Seven dark."

"And he _probably_ looked into Number Six through the first hole while
Martinez was boring the second. I suppose _you_ can tell which of the two
holes was bored first?" chuckled Tignol.

M. Paul started, paused in a flash of thought, and then, with sudden
eagerness: "I see, _that's it!_"

"What's it?" gasped the other.

"He bored _this_ hole first," said Coquenil rapidly, "it's the right-hand
one when you're in this room, the left-hand one when you're in Number
Seven. As you say, the murderer looked through the first hole while he
waited for the second to be bored; so, naturally, he fired through the hole
where his eye was. _That was his first great mistake_."

Tignol screwed up his face in perplexity. "What differe