“In France,” Peter Ruff continued, “there is a somewhat curious custom, which, despite a certain theatricality, yet has its points. The scene of a crime is visited, and its events, so far as may be, reconstructed. Let us suppose for a moment that we are now engaged upon something of the sort.”

Letty Shaw shrank back in her chair. Her thin white fingers were gripping its sides. Her eyes seemed to look upon terrible things.

“It is too—awful!” she faltered.

“Madam,” Peter Ruff said, firmly, “we seek the truth. Be so good as to humour me in this. Dory, will you go to the front door, stand upon the mat—so? You are Captain Sotherst—you have just entered. I am Austen Abbott. You, Miss Shaw, have just ordered me from the room. You see, I move toward the door. I open it—so. Miss Shaw,” he added, turning swiftly towards her, “once more will you assure me that every one who was in the flat that night, with the exception of your domestic servant, is present now?”

“Yes,” she murmured.

“Good! Then who,” he asked, suddenly pointing to a door on the left—“who is in that room?”

They had all crowded after him to the threshold—thronging around him as he stood face to face with John Dory. His finger never wavered—it was pointing steadily towards that closed door a few feet to the left. Suddenly Letty Shaw rushed past them with a loud shriek.

“You shall not go in!” she cried. “What business is it of his?”

She stood with her back to the door, her arms outstretched like a cross. Her cheeks were livid. Her eyes seemed starting from her head.

Peter Ruff and John Dory laid their hands upon the girl’s wrists. She clung to her place frantically. She was dragged from it, screaming. Peter Ruff, as was his right, entered first. Almost immediately he turned round, and his face was very grave.