“That is another line of thought. There are two, and I beg you will not tangle them. Line A, which concerns Lady Beatrice, has a vaguely sinister flavour, has it not?”

“I can make nothing of it.”

“Well, now, let us take up line B, which concerns Sir Robert. He is mad keen upon winning the Derby. He is in the hands of the Jews, and may at any moment be sold up and his racing stables seized by his creditors. He is a daring and desperate man. He derives his income from his sister. His sister’s maid is his willing tool. So far we seem to be on fairly safe ground, do we not?”

“But the crypt?”

“Ah, yes, the crypt! Let us suppose, Watson - it is merely a scandalous supposition, a hypothesis put forward for argument’s sake - that Sir Robert has done away with his sister.”

“My dear Holmes, it is out of the question.”

“Very possibly, Watson. Sir Robert is a man of an honourable stock. But you do occasionally find a carrion crow among the eagles. Let us for a moment argue upon this supposition. He could not fly the country until he had realized his fortune, and that fortune could only be realized by bringing off this coup with Shoscombe Prince. Therefore, he has still to stand his ground. To do this he would have to dispose of the body of his victim, and he would also have to find a substitute who would impersonate her. With the maid as his confidante that would not be impossible. The woman’s body might be conveyed to the crypt, which is a place so seldom visited, and it might be secretly destroyed at night in the furnace, leaving behind it such evidence as we have already seen. What say you to that, Watson?”

“Well, it is all possible if you grant the original monstrous supposition.”

“I think that there is a small experiment which we may try to-morrow, Watson, in order to throw some light on the matter. Meanwhile, if we mean to keep up our characters, I suggest that we have our host in for a glass of his own wine and hold some high converse upon eels and dace, which seems to be the straight road to his affections. We may chance to come upon some useful local gossip in the process.”

In the morning Holmes discovered that we had come without our spoon-bait for jack, which absolved us from fishing for the day. About eleven o’clock we started for a walk, and he obtained leave to take the black spaniel with us.

“This is the place,” said he as we came to two high park gates with heraldic griffins towering above them. “About midday, Mr. Barnes informs me, the old lady takes a drive, and the carriage must slow down while the gates are opened. When it comes through, and before it gathers speed, I want you, Watson, to stop the coachman with some question. Never mind me. I shall stand behind this holly-bush and see what I can see.”

It was not a long vigil. Within a quarter of an hour we saw the big open yellow barouche coming down the long avenue, with two splendid, high-stepping gray carriage horses in the shafts. Holmes crouched behind his bush with the dog. I stood unconcernedly swinging a cane in the roadway. A keeper ran out and the gates swung open.

The carriage had slowed to a walk, and I was able to get a good look at the occupants. A highly coloured young woman with flaxen hair and impudent eyes sat on the left. At her right was an elderly person with rounded back and a huddle of shawls about her face and shoulders which proclaimed the invalid. When the horses reached the highroad I held up my hand with an authoritative gesture, and as the coachman pulled up I inquired if Sir Robert was at Shoscombe Old Place.

At the same moment Holmes stepped out and released the spaniel. With a joyous cry it dashed forward to the carriage and sprang upon the step. Then in a moment its eager greeting changed to furious rage, and it snapped at the black skirt above it.