"Go ahead, old boy," thought Lupin, "cudgel your brains: you'll never spot it! Ah, if we had asked for Gilbert's pardon only, as Clarisse wished, you might have twigged the secret! But Vaucheray, that brute of a Vaucheray, there really could not be the least bond between Mme. Mergy and him.... Aha, by Jingo, it's my turn now!... He's watching me ... The inward soliloquy is turning upon myself... 'I wonder who that M. Nicole can be? Why has that little provincial usher devoted himself body and soul to Clarisse Mergy? Who is that old bore, if the truth were known? I made a mistake in not inquiring... I must look into this.... I must rip off the beggar's mask. For, after all, it's not natural that a man should take so much trouble about a matter in which he is not directly interested. Why should he also wish to save Gilbert and Vaucheray? Why? Why should he? ... " Lupin turned his head away. "Look out!... Look out!... There's a notion passing through that red-tape-merchant's skull: a confused notion which he can't put into words. Hang it all, he mustn't suspect M. Lupin under M. Nicole! The thing's complicated enough enough as it is, in all conscience!...

But there was a welcome interruption. Prasville's secretary came to say that the audience would take place in an hour's time.

"Very well. Thank you," said Prasville. "That will do."

And, resuming the interview, with no further circumlocution, speaking like a man who means to put a thing through, he declared:

"I think that we shall be able to manage it. But, first of all, so that I may do what I have undertaken to do, I want more precise information, fuller details. Where was the paper?"

"In the crystal stopper, as we thought," said Mme. Mergy.

"And where was the crystal stopper?"

"In an object which Daubrecq came and fetched, a few days ago, from the writing-desk in his study in the Square Lamartine, an object which I took from him yesterday."

"What sort of object?"

"Simply a packet of tobacco, Maryland tobacco, which used to lie about on the desk."

Prasville was petrified. He muttered, guilelessly:

"Oh, if I had only known! I've had my hand on that packet of Maryland a dozen times! How stupid of me!"

"What does it matter?" said Clarisse. "The great thing is that the discovery is made."

Prasville pulled a face which implied that the discovery would have been much pleasanter if he himself had made it. Then he asked:

"So you have the list?"

"Yes."

"Yes."

"Show it to me."

And, when Clarisse hesitated, he added:

"Oh, please, don't be afraid! The list belongs to you, and I will give it back to you. But you must understand that I cannot take the step in question without making certain."

Clarisse consulted M. Nicole with a glance which did not escape Prasville. Then she said:

"Here it is."

He seized the scrap of paper with a certain excitement, examined it and almost immediately said:

"Yes, yes... the secretary's writing: I recognize it.... And the signature of the chairman of the company: the signature in red.... Besides, I have other proofs.... For instance, the torn piece which completes the left-hand top corner of this sheet..."

She was as good as her word, but there was nothing which was helpful in our investigation. She had no reason to think that her fiance had any hidden enemy, but she admitted that she had had several warm admirers.

“May I ask if Mr. Ian Murdoch was one of them?”

She blushed and seemed confused.

“There was a time when I thought he was. But that was all changed when he understood the relations between Fitzroy and myself.”

Again the shadow round this strange man seemed to me to be taking more definite shape. His record must be examined. His rooms must be privately searched. Stackhurst was a willing collaborator, for in his mind also suspicions were forming. We returned from our visit to The Haven with the hope that one free end of this tangled skein was already in our hands.

A week passed. The inquest had thrown no light upon the matter and had been adjourned for further evidence. Stackhurst had made discreet inquiry about his subordinate, and there had been a superficial search of his room, but without result. Personally, I had gone over the whole ground again, both physically and mentally, but with no new conclusions. In all my chronicles the reader will find no case which brought me so completely to the limit of my powers. Even my imagination could conceive no solution to the mystery. And then there came the incident of the dog.

It was my old housekeeper who heard of it first by that strange wireless by which such people collect the news of the countryside.

“Sad story this, sir, about Mr. McPherson’s dog,” said she one evening.

I do not encourage such conversations, but the words arrested my attention.

“What of Mr. McPherson’s dog?”

“Dead, sir. Died of grief for its master.”

“Who told you this?”

“Why, sir, everyone is talking of it. It took on terrible, and has eaten nothing for a week. Then to-day two of the young gentlemen from The Gables found it dead — down on the beach, sir, at the very place where its master met his end.”

“At the very place.” The words stood out clear in my memory. Some dim perception that the matter was vital rose in my mind. That the dog should die was after the beautiful, faithful nature of dogs. But “in the very place”! Why should this lonely beach be fatal to it? Was it possible that it also had been sacrificed to some revengeful feud? Was it possible —? Yes, the perception was dim, but already something was building up in my mind. In a few minutes I was on my way to The Gables, where I found Stackhurst in his study. At my request he sent for Sudbury and Blount, the two students who had found the dog.

“Yes, it lay on the very edge of the pool,” said one of them. “It must have followed the trail of its dead master.”

I saw the faithful little creature, an Airedale terrier, laid out upon the mat in the hall. The body was stiff and rigid, the eyes projecting, and the limbs contorted. There was agony in every line of it.