Caldew's resentment waned under this compliment to his professional skill.

"The trick would have worked, too, if I hadn't been called downstairs," he said. "The girl was quick enough to get into the room while I was out of it. Not that it mattered much, as things turned out, but it is a strange thing about this necklace, isn't it?"

"Very. Has Merrington told you all about it?"

"Yes, and he gave me a rare wigging for not discovering the loss. Between ourselves, I do not think that I was treated quite fairly about it. Miss Heredith never said a word to me about a jewel-case being in the room. She took it downstairs before I arrived, and never mentioned it when I asked her if anything had been stolen. If she had told me I should have had the case opened. But that didn't weigh with Merrington. He's beastly unfair, and never loses a chance to put the blame on to somebody else when anything goes wrong."

"I am sorry if you got into trouble through my action in informing him," said Colwyn. "But of course you must realize that a discovery of such importance could not be kept secret."

"That's quite true," replied Caldew, in a softened voice. "Fortunately, it does not affect the issue, one way or another. Mr. Heredith believes that Hazel Rath is innocent, and I suppose that is why he has called you into the case. But she is guilty, right enough. I tried to make that clear to Mr. Heredith, but he appears to be a man of fixed ideas. The question is, what has become of the necklace? My own impression is that she has hidden it somewhere. She had no opportunity to dispose of it before she was arrested."

"That means that you think she has stolen it."

"Why, of course-" Caldew's confident tone died away at the expression of his companion's face. "Don't you?"

"I do not."

"Why not?"

"For one thing, the jewel-case was locked. How did the girl know where the key was kept?"

"She might have got the knowledge from her mother. Mrs. Rath, as the housekeeper, would probably know all about the keys of the household."

"Of the ordinary keys-yes. But that knowledge was hardly likely to extend to Mrs. Heredith's private keys, unless Miss Heredith told her. Even if Hazel Rath did know where the key was kept, it is difficult to believe that she searched for it after committing the murder, and then restored it to the drawer where it was kept. That argues too much cold-blooded deliberation even in a murderer, and more especially when the murderer is supposed to be a young girl."

"I am not so sure of that," responded Caldew, with a shake of the head. "Murder is a cold-blooded crime."

"On the contrary, murders are almost invariably committed under the influence of the strongest excitement, even when the incentive is gain, and the murder has been deeply premeditated. That is a remarkable truth in the psychology of murder. But the important fact about the theft of the necklace is that even if Hazel Rath knew where the key of the jewel-case was kept she had not time to obtain it from the drawer on the other side of the bed, steal the necklace, restore the key to its place, and escape from the room before the guests from downstairs entered the bedroom. If Hazel Rath was indeed the murderess, time was of paramount importance to her. She must have realized that the scream of her victim would alarm the household downstairs, and that some of the men must have started upstairs before the subsequent shot was fired."

Caldew was silent for a s.p.a.ce, cogitating over these points with a troubled look which contrasted with his previous confident expressions of opinion about the case. His inward perturbation was made manifest in the question:

"Do you also share Mr. Heredith's view that Hazel Rath is innocent?"

"I cannot say. The facts against her are very strong."

"Of course they are strong!" exclaimed Caldew eagerly, as though clutching this guarded expression of opinion as a buoy for his own sinking conviction. "They are so strong that it is quite certain she committed the murder."

Colwyn remained silent. A statement which was merely an expression of opinion did not call for words.

Caldew, always impressionable, became uneasy under his companion's silence, and that uneasiness was tinctured in his mind with such a dread of the possibility of mistake that it flowed forth in impulsive words:

"I wish you would tell me what you really think of the case, Mr. Colwyn. I have been waiting for years for the chance of handling a big murder like this, and now that it has come my way I should like to pull it off. It means a lot to me," he added simply.

Colwyn reflected that he had already given away more information about the Heredith case than his judgment approved or his conscience dictated. But his kindly nature prompted him to help the anxious young man seated in front of him, who had so much more than he to gain by success.

"I think there is more in this case than you and Merrington have yet brought to light," he said.

"I suppose there is, if it is proved that Hazel Rath did not steal the necklace. But have you found out anything else besides the loss of the necklace?"

Colwyn did not directly reply. He was glancing over the depositions again.

"There are one or two curious points here," he remarked, as he turned over the leaves. "In the first place, the ammunition expert who was called at the inquest to give evidence about the bullet extracted from the body testified that in weight and in length it corresponded with the seven millimetre bullet made for a pinfire revolver. The bullet had undoubtedly been fired from the revolver which you found in Mrs. Rath's rooms. Bullets for English revolvers are not graded in millimetres, but there appears to be sufficient demand for this size to cause British firms to manufacture them. The nearest size in central-fire cartridge to seven millimetres is called the 300, which is .3 of an inch. Seven millimetres is .276 of an inch. The point to which I want to draw your attention is the extreme slightness and smallness of the revolver with which Mrs. Heredith was killed. As Captain Nepcote told Merrington yesterday, it is little more than a toy."

"That struck me as soon as I saw it," said Caldew. "But I do not see what bearing the fact has on the case, one way or another."

"Nevertheless, it is a point not without importance, when it is considered in conjunction with the other circ.u.mstances of the case. The evidence of the Government pathologist is also of interest. After stating the cause of death to be heart failure due to haemorrhage consequent upon the pa.s.sage of the bullet through the lung, he mentions that there was a large scorched hole through the rest-gown and undergarment which Mrs. Heredith was wearing at the time she was murdered."

"I noticed that when I was examining the body."

"Was the dress-stuff smouldering when you saw the body?"

"No; but there was a smell of a burning fabric in the room."

"The Government pathologist says that the burnt hole was nearly two inches across, but he also states that the punctured wound made by the bullet was about the size of a threepenny piece. The disparity suggests two facts. In the first place, the shot must have been fired at very close range-very close indeed, considering the smallness of the revolver and the largeness of the burnt hole. In the next place, somebody must have extinguished the burning fabric before you arrived, otherwise it would have smouldered in an ever-widening ring until the whole of the dead woman's garments were destroyed."

"Mrs. Heredith may have extinguished it herself in her dying moments," said Caldew, who had been following his companion's deductions with the closest attention.

"That is unlikely, in view of the nature of her injuries. The bullet, after traversing the left lung, lodged in the spinal column. After such a wound Mrs. Heredith was not likely to be conscious of her actions."

"It may have been extinguished by Musard, who tried to stop the flow of blood while Mrs. Heredith was dying."

"He would have mentioned it to you. It is my intention to ask him, but my own opinion is that we are faced with a different explanation."

"What is that?"

"The presence of another person in the room."

"Somebody who escaped through the window!" exclaimed Caldew, placing his own interpretation on the deduction. "Do you suspect anybody?"

"Not exactly. But I intend to investigate Captain Nepcote's actions on the night of the murder."

Caldew, who lacked some of the information possessed by his companion, found this jump too great for his mind to follow.

"For what purpose?" he asked. "Nepcote returned to France before the murder was committed."

"He did not. He stayed in London that night, and did not return to France until the following day. He explained that yesterday by stating that when he reached London after leaving the moat-house he found another telegram from the War Office extending his leave for twenty-four hours."

"Merrington said nothing of this to me. All he told me was that you and he had seen Nepcote, who identified the revolver as his property, and said that he had left it behind at the moat-house by accident."

"Merrington is a man of fixed ideas, to use your phrase. He insisted on trying to fit in the loss of the necklace with his own theory of Hazel Rath's guilt. It was his obstinacy which led him to commit the folly of going to see Captain Nepcote before endeavouring to trace the missing necklace. It is only fair to Nepcote to add that he volunteered the information that he did not return to France on the night of the murder."

"That does not seem like the action of a man with anything to hide," commented Caldew thoughtfully.

"Unless he was facing a dangerous situation. In that case, frankness would be his best course to remove Merrington's suspicions. The fact that the murder was committed with his revolver is in itself a suspicious circ.u.mstance, in spite of the apparently plausible explanation. I have realized that all along. I had also previously acquainted Merrington with the fact that Nepcote did not return to France on the night of the murder, as was supposed. Merrington led up to that point skilfully enough, but it struck me that Nepcote saw the trap, and took the boldest course. It gave him time, at all events."

"Time for what?"

"Time to profit by Merrington's folly in putting him on his guard. Time to permit him to make his escape, if he is actually implicated in the crime."