Suddenly my attention was arrested by a weedy looking young man rushing down the street at a great pace. It was the expression on his face that was extraordinary⁠—a curious mingling of terror and agitation.

“Look, Poirot!” I said.

He leant forward.

“ Tiens! ” he said. “It is Mr. Mace, from the chemist’s shop. He is coming here.”

The young man came to a halt before Leastways Cottage, and, after hesitating a moment, pounded vigorously at the door.

“A little minute,” cried Poirot from the window. “I come.”