Holmes sat for some time in silent thought. He had lit the oldest and foulest of his pipes.

“I am not clear yet what you want me to do in this matter, Mr. Mason,” he said at last. “Can’t you make it more definite?”

“Perhaps this will make it more definite, Mr. Holmes,” said our visitor.

He took a paper from his pocket, and, unwrapping it carefully, he exposed a charred fragment of bone.

Holmes examined it with interest.

“Where did you get it?”

“There is a central heating furnace in the cellar under Lady Beatrice’s room. It‘s been off for some time, but Sir Robert complained of cold and had it on again.

Harvey runs it — he’s one of my lads. This very morning he came to me with this which he found raking out the cinders. He didn’t like the look of it.”

“Nor do I,” said Holmes. “What do you make of it, Watson?”

It was burned to a black cinder, but there could be no question as to its anatomical significance.

“It’s the upper condyle of a human femur,” said I.

“Exactly!” Holmes had become very serious. “When does this lad tend to the furnace?”

“He makes it up every evening and then leaves it.”

“Then anyone anyone could visit it during the night?”

“Yes, sir.”

“Can you enter it from outside?”

“There is one door from outside. There is another which leads up by a stair to the passage in which Lady Beatrice’s room is situated.”

“These are deep waters, Mr. Mason; deep and rather dirty. You say that Sir Robert was not at home last night?”

“No, sir.”

“Then, whoever was burning bones, it was not he.”

“That’s true, sir.”

“What is the name of that inn you spoke of?”

“The Green Dragon.”

“Is there good fishing in that part of Berkshire?” The honest trainer showed very clearly upon his face that he was convinced that yet another lunatic had come into his harassed life.

“Well, sir, I’ve heard there are trout in the mill-stream and pike in the Hall lake.”

“That’s good enough. Watson and I are famous fishermen — are we not, Watson? You may address us in future at the Green Dragon. We should reach it to-night. I need not say that we don’t want to see you, Mr. Mason, but a note will reach us, and no doubt I could find you if I want you. When we have gone a little farther into the matter I will let you have a considered opinion.”

Thus it was that on a bright May evening Holmes and I found ourselves alone in a first-class carriage and bound for the little “halt-on-demand” station of Shoscombe. The rack above us was covered with a formidable litter of rods, reels, and baskets. On reaching our destination a short drive took us to an old-fashioned tavern, where a sporting host, Josiah Barnes, entered eagerly into our plans for the extirpation of the fish of the neighbourhood.

"Whom did she ask for?"

"M. Michel Beaumont," replied the servant.

"Queer. And why has she called?"

"All she said was that it was about the Enghien business... So I thought that... "

"What! The Enghien business! Then she knows that I am mixed up in that business... She knows that, by applying here... "

"I could not get anything out of her, but I thought, all the same, that I had better let her in."

"Quite right. Where is she?"

"In the drawing-room. I've put on the lights."

Lupin walked briskly across the hall and opened the door of the drawing-room:

"What are you talking about?" he said, to his man. "There's no one here."

"No one here?" said Achille, running up.

And the room, in fact, was empty.

"Well, on my word, this takes the cake!" cried the servant. "It wasn't twenty minutes ago that I came and had a look, to make sure. She was sitting over there. And there's nothing wrong with my eyesight, you know."

"Look here, look here," said Lupin, irritably. "Where were you while the woman was waiting?"

"In the hail, governor! I never left the hail for a second! I should have seen her go out, blow it!"

"Still, she's not here now... "

"So I see," moaned the man, quite flabbergasted.

"She must have got tired of waiting and gone away. But, dash it all, I should like to know how she got out!"

"How she got out?" said Lupin. "It doesn't take a wizard to tell that."

"What do you mean?"

"She got out through the window. Look, it's still ajar We are on the ground-floor... The street is almost always deserted, in the evenings. There's no doubt about it."

He had looked around him and satisfied himself that nothing had been taken away or moved. The room, for that matter, contained no knicknack of any value, no important paper that might have explained the woman's visit, followed by her sudden disappearance. And yet why that inexplicable flight?

"Has any one telephoned?" he asked.

"No."

"Any letters?"

"Yes, one letter by the last post."

"Where is it?"

"I put it on your mantel-piece, governor, as usual."

Lupin's bedroom was next to the drawing-room, but Lupin had permanently bolted the door between the two. He, therefore, had to go through the hall again.

Lupin switched on the electric light and, the next moment, said:

"I don't see it... "

"Yes... I put it next to the flower-bowl."

"There's nothing here at all."

"You must be looking in the wrong place, governor."

But Achille moved the bowl, lifted the clock, bent down to the grate, in vain: the letter was not there.

"Oh blast it, blast it!" he muttered. "She's done it... she's taken it... And then, when she had the letter, she cleared out... Oh, the slut!... "

Lupin said:

"You're mad! There's no way through between the two rooms."

"Then who did take it, governor?"

They were both of them silent. Lupin strove to control his anger and collect his ideas. He asked:

"Did you look at the envelope?"

"Yes."

"Anything particular about it?"

""Yes, it looked as if it had been written in a hurry, or scribbled, rather."