“It seems to me utterly irrelevant,” I declared.

“I wouldn’t say that,” demurred the inspector. “But I must confess I think Mr. Poirot here harps on it a little too much. We’ve better clues than that. The fingerprints on the dagger, for instance.”

Poirot became suddenly very foreign in manner, as he often did when excited over anything.

“M. l’inspecteur,” he said, “beware of the blind⁠—the blind⁠— comment dire ?⁠—the little street that has no end to it.”

Inspector Raglan stared, but I was quicker.

“You mean a blind alley?” I said.

“That is it⁠—the blind street that leads nowhere. So it may be with those fingerprints⁠—they may lead you nowhere.”