And, suddenly, Lupin remembered: two years ago, Prasville and Daubrecq the deputy had had a personal encounter on the Place du Palais-Bourbon. The incident made a great stir at the time. No one knew the cause of it. Prasville had sent his seconds to Daubrecq on the same day; but Daubrecq refused to fight.

A little while later, Prasville was appointed secretary-general.

"Very odd, very odd," said Lupin, who remained plunged in thought, while continuing to observe Prasvile's movements.

At seven o'clock Prasville's group of men moved away a few yards, in the direction of the Avenue Henri-Martin. The door of a small garden on the right of the house opened and Daubrecq appeared. The two detectives followed close behind him and, when he took the Rue-Taitbout train, jumped on after him.

Prasville at once walked across the square and rang the bell. The garden-gate was between the house and the porter's lodge. The portress came and opened it. There was a brief conversation, after which Prasville and his companions were admitted.

"A domiciliary visit," said Lupin. "Secret and illegal. By the strict rules of politeness, I ought to be invited. My presence is indispensable."

Without the least hesitation hesitation he went up to the house, the door of which had not been closed, and, passing in front of the portress, who was casting her eyes outside, he asked, in the hurried tones of a person who is late for an appointment:

"Have the gentlemen come?"

"Yes, you will find them in the study."

His plan was quite simple: if any one met him, he would pretend to be a tradesman. But there was no need for this subterfuge. He was able, after crossing an empty hail, to enter a dining-room which also had no one in it, but which, through the panes of a glass partition that separated the dining-room from the study, afforded him a view of Prasville and his five companions.

Prasville opened all the drawers with the aid of false keys. Next, he examined all the papers, while his companions took down the books from the shelves, shook the pages of each separately and felt inside the bindings.

"Of course, it's a paper they're looking for," said Lupin. "Bank-notes, perhaps... "

Prasville exclaimed:

"Whatrot! We shan't find a thing!"

Yet he obviously did not abandon all hope of discovering what he wanted, for he suddenly seized the four bottles in a liqueur-stand, took out the four stoppers and inspected them.

"Hullo!" thought Lupin. "Now he's going for decanter-stoppers! Then it's not a question of a paper? Well, I give it up."

Prasville next lifted and examined different objects; and he asked:

"How often have you been here?"

"Six times last winter," was the reply.

"And you have searched the house thoroughly?"

"Every one of the rooms, for days at a time, while he was visiting his constituency."

"Still... still ... ." And he added, "Has he no servant at present?"

"No, he is looking for one. He has his meals out and the portress keeps the house as best she can. The woman is devoted to us... "

“Yes, I would swear to his yellow face — a mean dog, I should say. What could he have in common with Sir Robert?”

Holmes sat for some time lost in thought.

“Who keeps Lady Beatrice Falder company?” he asked at last.

“There is her maid, Carrie Evans. She has been with her this five years.”

“And is, no doubt, devoted?”

Mr. Mason shuffled uncomfortably.

“She’s devoted enough,” he answered at last. “But I won‘t say to whom.”

“Ah!” said Holmes.

“I can’t tell tales out of school.”

“I quite understand, Mr. Mason. Of course, the situation is clear enough. From Dr. Watson’s description of Sir Robert I can realize that no woman is safe from him. Don’t you think the quarrel between brother and sister may lie there?”

“Well, the scandal has been pretty clear for a long time.”

“But she may not have seen it before. Let us suppose that she has suddenly found it out. She wants to get rid of the woman. Her brother will not permit it. The invalid, with her weak heart and inability to get about, has no means of enforcing her will. The hated maid is still tied to her. The lady refuses to speak, sulks, takes to drink. Sir Robert in his anger takes her pet spaniel away from her. Does not all this hang together?”

“Well, it might do — so far as it goes.”

“Exactly! As far as it goes. How would all that bear upon the visits by night to the old crypt? We can’t fit that into our plot.”

“No, sir, and there is something more that I can’t fit in. Why should Sir Robert want to dig up a dead body?”

Holmes sat up abruptly.

“We only found it out yesterday — after I had written to you. Yesterday Sir Robert had gone to London, so Stephens and I went down to the crypt. It was all in order, sir, except that in one corner was a bit of a human body.”

“You informed the police, I suppose?”

Our visitor smiled grimly.

“Well, sir, I think it would hardly interest them. It was just the head and a few bones of a mummy. It may have been a thousand years old. But it wasn’t there before. That I‘ll swear, and so will Stephens. It had been stowed away in a corner and covered over with a board, but that corner had always been empty before.”

“What did you do with it?”

“Well, we just left it there.”

“That was wise. You say Sir Robert was away yesterday. Has he returned?”

“We expect him back to-day.”

“When did Sir Robert give away his sister’s dog?”

“It was just a week ago to-day. The creature was howling outside the old wellhouse, and Sir Robert was in one of his tantrums that morning. He caught it up, and I thought he would have killed it. Then he gave it to Sandy Bain, the jockey, and told him to take the dog to old Barnes at the Green Dragon, for he never wished to see it again.”