“I would hardly go so far as to say that, my dear Watson. The fact is that there is one really serious flaw in this evidence to which our friend attaches so much importance.”

“Indeed, Holmes! What is it?”

“Only this: that I know that that mark was not there when I examined the hall yesterday. And now, Watson, let us have a little stroll round in the sunshine.”

With a confused brain, but with a heart into which some warmth of hope was returning, I accompanied my friend in a walk round the garden. Holmes took each face of the house in turn, and examined it with great interest. He then led the way inside, and went over the whole building from basement to attic. Most of the rooms were unfurnished, but none the less Holmes inspected them all minutely. Finally, on the top corridor, which ran outside three untenanted bedrooms, he again was seized with a spasm of merriment.

“There are really some very unique features about this case, Watson,” said he. “I think it is time now that we took our friend Lestrade into our confidence. He has had his little smile at our expense, and perhaps we may do as much by him, if my reading of this problem proves to be correct. Yes, yes, I think I see how we should approach it.”

The Scotland Yard inspector was still writing in the parlour when Holmes interrupted him.

“I understood that you were writing a report of this case,” said he.

“So I am.”

“Don’t you think it may be a little premature? I can’t help thinking that your evidence is not complete.”

Lestrade knew my friend too well to disregard his words. He laid down his pen and looked curiously at him.

“What do you mean, Mr. Holmes?”

“Only that there is an important witness whom you have not seen.”

“Can you produce him?”

“I think I can.”

“Then do so.”

“I will do my best. How many constables have you?”

“There are three within call.”

“Excellent!” said Holmes. “May I ask if they are all large, able-bodied men with powerful voices?”

“I have no doubt they are, though I fail to see what their voices have to do with it.”

“Perhaps I can help you to see that and one or two other things as well, ” said Holmes. “Kindly summon your men, and I will try.”

Five minutes later, three policemen had assembled in the hall.

“In the outhouse you will find a considerable quantity of straw,” said Holmes. “I will ask you to carry in two bundles of it. I think it will be of the greatest assistance in producing the witness whom I require. Thank you very much. I believe you have some matches in your pocket, Watson. Now, Mr. Lestrade, I will ask you all to accompany me to the top landing.”

As I have said, there was a broad corridor there, which ran outside three empty bedrooms. At one end of the corridor we were all marshalled by Sherlock Holmes, the constables grinning and Lestrade staring at my friend with amazement, expectation, and derision chasing each other across his features. Holmes stood before us with the air of a conjurer who is performing a trick.

“Would you kindly send one of your constables for two buckets of water? Put the straw on the floor here, free from the wall on either side. Now I think that we are all ready.”

Lestrade’s face had begun to grow red and angry.

“I don’t know whether you are playing a game with us, Mr. Sherlock Holmes,” said he. “If you know anything, you can surely say it without all this tomfoolery.”