“Strange,” he murmured. “We all have the little grey cells. And so few of us know how to use them. Good morning, Signor Ascanio. I believe your story. It is very much as I had imagined. But I had to make sure.”

After bowing his guest out, Poirot returned to his arm-chair and smiled at me.

“Let us hear M. le Capitaine Hastings on the case?”

“Well, I suppose Ascanio is right—somebody impersonated him.”

“Never, never will you use the brains the good God has given you. Recall to yourself some words I uttered after leaving the flat that night. I referred to the window-curtains not being drawn. We are in the month of June. It is still light at eight o’clock. The light is failing by half-past. Ça vous dit quelque chose? I perceive a struggling impression that you will arrive some day. Now let us continue. The coffee was, as I said, very black. Count Foscatini’s teeth were magnificently white. Coffee stains the teeth. We reason from that that Count Foscatini did not drink any coffee. Yet there was coffee in all three cups. Why should anyone pretend Count Foscatini had drunk coffee when he had not done so?”

I shook my head, utterly bewildered.

“Come, I will help you. What evidence have we that Ascanio and his friend, or two men posing as them, ever came to the flat that night? Nobody saw them go in; nobody saw them go out. We have the evidence of one man and of a host of inanimate objects.”

“You mean?”

“I mean knives and forks and plates and empty dishes. Ah, but it was a clever idea! Graves is a thief and a scoundrel, but what a man of method! He overhears a portion of the conversation in the morning, enough to realize that Ascanio will be in awkward position to defend himself. The following evening, about eight o’clock, he tells his master he is wanted at the telephone. Foscatini sits down, stretches out his hand to the telephone, and from behind Graves strikes him down with the marble figure. Then quickly to the service telephone—dinner for three! It comes, he lays the table, dirties the plates, knives, and forks, etc. But he has to get rid of the food too. Not only is he a man of brain; he has a resolute and capacious stomach! But after eating three tournedos, the rice soufflé is too much for him! He even smokes a cigar and two cigarettes to carry out the illusion. Ah, but it was magnificently thorough! Then, having moved on the hands of the clock to 8.47, he smashes it and stops it. The one thing he does not do is to draw the curtains. But if there had been a real dinner party the curtains would have been drawn as soon as the light began to fail. Then he hurries out, mentioning the guests to the lift man in passing. He hurries to a telephone box, and as near as possible to 8.47 rings up the doctor with his master’s dying cry. So successful is his idea that no one ever inquires if a call was put through from Flat ii at that time.”

“Except Hercule Poirot, I suppose?” I said sarcastically.