On hearing Captain Stanhill's question, Merrington paused abruptly in his impatient pacing of the carpet, and glanced at him covertly from his deep-set little eyes. If he had consulted his own feelings he would have told the Chief Constable that it was not the time to air theories about the crime. But in his present position it behoved him to walk warily and not make an enemy of his colleague. If there was to be an outburst of public indignation because the murderer in this case had not been immediately discovered and brought to justice, it would be just as well if the county police shared the burden of responsibility. Merrington realized that he could best make Captain Stanhill feel his responsibility by taking him fully into his confidence. He was aware that he had practically ignored the Chief Constable in the course of the day's investigations, and it was desirable to remove any feeling that treatment may have caused. Superintendent Merrington had the greatest contempt for the county police, but there were times when it was judicious to dissemble that feeling. The present moment was one of them.

Captain Stanhill, on his part, cherished no animosity against his companion for his cavalier treatment of him. He realized his own inexperience in crime detection, and had been quite willing that Superintendent Merrington should take the lead in the investigations, which he had assisted to the best of his ability. He thought Merrington rather an unpleasant type, but he was overawed by his great reputation as a detective, and impressed by his energy and massive self-confidence. The Chief Constable had not asserted his own official position, because he was aware that he was unable to give competent help in such a baffling case. He was, above all things, anxious that the murderer of Violet Heredith should be captured and brought to justice as speedily as possible, and he had no thought of his personal dignity so long as that end was achieved.

The abstract ideal of human justice is supposed to be based on the threefold aims of punishment, prevention, and reformation, but the heart of the average man, when confronted by grevious wrong, is swayed by no higher impulse than immediate retribution on the wrongdoer. Captain Stanhill was an average man, and his feelings, harrowed by the spectacle of the bleeding corpse of the young wife, and the pitiful condition to which her murder had reduced her young husband, clamoured for retribution, swift, complete, and implacable, on the being who had committed this horrible crime. And he hoped that the famous detective would be able to assure him that his desire was likely to have a speedy attainment. That was why he asked Merrington whether he had formed any theory about the crime.

"It would be too much to say that I have formed a theory," replied Merrington, in response to Captain Stanhill's question. "It is necessary to have clues for the formation of a theory, and in this case we are faced with a complete absence of clues."

"Do you not think that the trinket found by Detective Caldew in Mrs. Heredith's bedroom has some bearing on the murder?" said Captain Stanhill.

"I attach no importance to it. There were a number of persons in the bedroom after the murder was committed, and any of them might have dropped the ornament. Or it may have been lost there days before by a servant, and escaped notice."

"But it was picked up again during Caldew's absence from the room. Do you not regard that as suspicious? Detective Caldew, when he was relating the incident to us this morning, seemed to think that the trinket belonged to the murderer, who took the risk of returning to the room to recover it for fear it might form a clue leading to discovery."

"Caldew reads too much into his discovery," replied Merrington, with an indulgent smile. "Like all young detectives, he is inclined to attach undue importance to small points. As I told him, I cannot imagine a murderer taking such a desperate risk as to return to the spot where he had killed his victim, in order to search for a trinket he had dropped. Caldew may have concealed the brooch so effectually in the thick folds of the velvet carpet that he could not find it again when he looked for it on his return to the room. That explanation strikes me as probable as his own theory of a mysterious midnight intruder returning to search for it while he was out of the room. The trinket may have some connection with the crime, or it may not, but as I have not seen it I prefer to leave it out of my calculation altogether. This case is going to be difficult enough to solve without chasing chimeras. But to return to your question. Although I have not actually formed a theory, my preliminary investigations of the circumstances have led me to arrive at certain conclusions and to exclude possibilities I was at first inclined to adopt. I will go over the case in detail, and then you will see for yourself the conclusions I have formed, and understand how I have arrived at them.

"In the first place, the greatest problem of this murder is the apparent lack of motive. There seems to be no reason why this young lady should have been killed. She had only recently been married, and, apparently, married happily, to a wealthy young man of good family, who was very much in love with her. It is obvious that money difficulties have nothing to do with the crime. Her husband is the only son of a wealthy father, and he is able to give his wife everything that a woman needs for her happiness and comfort. She is cherished, petted, and loved, and has a beautiful home. Who, therefore, had an object in putting an end to this young woman's life in her own home, in circumstances and conditions attended with the utmost possibility of discovery and capture? The perpetrator of the deed must have acted from some very strong motive or impulse to venture into a country-house full of people, at a time when everybody was indoors, in order to kill his victim.

"In a seemingly purposeless murder like this, a certain amount of suspicion gathers round the other members of the household. Human nature being what it is, one should never take anything for granted, but should always be on the watch for hidden motives. But in this case the members of the household, with the exception of Miss Heredith, were downstairs in the dining-room at the time the murder was committed. Miss Heredith left the room a few minutes before the shot was heard. You will recall that she volunteered that statement to us this morning. It occurred to me at the time that that may have been bluff to put us off the scent. Clever criminals often do that kind of thing. My suspicions against her were strengthened by the additional fact that Miss Heredith did not like her nephew's wife. She masked the fact beneath a well-bred semblance of grief and horror, but it was plain as a pikestaff to me. But, after thinking over all the circumstances, I came to the conclusion that she had nothing whatever to do with it."