“An idea⁠—an indication, no more. But the case certainly grows in interest. Unique, perfectly unique, and yet why not? I do not see any indications of bleeding on the line.”

“There were hardly any.”

“But I understand that there was a considerable wound.”

“The bone was crushed, but there was no great external injury.”

“And yet one would have expected some bleeding. Would it be possible for me to inspect the train which contained the passenger who heard the thud of a fall in the fog?”

“I fear not, Mr. Holmes. The train has been broken up before now, and the carriages redistributed.”