"For Heaven's sake, Poirot," I urged, "let us be up and at them."

"Admirable, mon ami, admirable! Up where, and at whom? Be precise, I beg of you."

"At the Big Four, of course."

"Cela va sans dire. But how would you set about it?"

"The police," I hazarded doubtfully.

Poirot smiled.

"They would accuse us of romancing. We have nothing to go upon—nothing whatever. We must wait."

"Wait for what?"

"Wait for them to make a move. See now, in England you all comprehend and adore la boxe. If one man does not make a move, the other must, and by permitting the adversary to make the attack one learns something about him. That is our part—to let the other side make the attack."

"You think they will?" I said doubtfully.