There was a pause, then Katherine said:
"Yes—I think I know."
Poirot leant across the table towards her.
"I am not satisfied, Mademoiselle; no, I am not satisfied. The facts, the main facts, led straight to Monsieur Kettering. But there is one thing that has been left out of account."
"And what is that?"
"The disfigured face of the victim. I have asked myself, Mademoiselle, a hundred times, 'Was Derek Kettering the kind of man who would deal that smashing blow after having committed the murder?' What end would it serve? What purpose would it accomplish? Was it a likely action for one of Monsieur Kettering's temperament? And, Mademoiselle, the answer to these questions is profoundly unsatisfactory. Again and again I go back to that one point—'why?' And the only things I have to help me to a solution of the problem are these."
He whipped out his pocket-book and extracted something from it which he held between his finger and thumb.
"Do you remember, Mademoiselle? You saw me take these hairs from the rug in the railway carriage."
Katherine leant forward, scrutinizing the hairs keenly.
Poirot nodded his head slowly several times.
"They suggest nothing to you, I see that, Mademoiselle. And yet—I think somehow that you see a good deal."
"I have had ideas," said Katherine slowly, "curious
