On his way to Chidelham, Caldew again pondered over the murder, and for the first time seriously asked himself whether Miss Heredith could have committed the crime. He had glanced at that possibility before, and had practically dismissed it on the score of lack of motive, but his sister's story of the differences between Miss Heredith and her nephew's wife supplied that deficiency in a startling degree. In reviewing the whole of the circumstances by the light of the information his sister had given him, it now seemed to him that Miss Heredith fitted into the crime in a remarkable way.

The most important fact leading to that inference was that she alone, of all the inmates of the moat-house the previous night, was out of the dining-room when the murder was committed. That supposition took no cognizance of the servants, but Caldew had all along eliminated the servants in his consideration of the crime. In the next place, it supplied an explanation for the disappearance of the bar brooch from the bedroom. In all likelihood the butler had first acquainted his mistress with his discovery of the unlocked staircase door, and she, realizing where she had dropped her brooch, had seized upon the opportunity to request Musard to call the detective downstairs and tell him about the door. In his absence she returned to the bedroom for the brooch.

This theory seemed plausible enough at first blush, but as Caldew examined it closely several objections arose in his mind. The hidden motive of the crime, as innocently laid bare by his sister, was strong, but was it strong enough to impel a woman like Miss Heredith, with the rigid principles of her birth, breeding, and caste, and a woman, moreover, who had spent her life in good works, to commit such an atrocious murder? Caldew considered this point long and thoughtfully. With his keener imagination he differed from Merrington by relying to some extent on external impressions, and he could not shake off his first impression of Miss Heredith as a woman of exceptionally good type. He had to admit to himself that her graciousness and dignity were not the qualities usually associated with a murderer. Religion, hypocrisy, smugness, plausibility; these were the commonest counterfeit qualities of criminals; not dignity, worth, and pride.

There was, of course, the possibility that Miss Heredith, grown imperious with her long unquestioned sway at the moat-house, had quarrelled with the young wife, and committed the murder in a sudden gust of passion. The most unlikely murders had been committed under the sway of impulse. Caldew recalled that Miss Heredith had been the last person to see the murdered woman alive, and nobody except herself knew what had occurred at that interview. It might be that the young wife had said something to her which rankled so deeply that she conceived the idea of murdering her.

Caldew, on reaching this stage of his reasoning, shook his head doubtfully. He had to admit to himself that such a theory did not ring true. If Miss Heredith had been maddened by some insult at the afternoon's interview, she was far more likely to have killed Mrs. Heredith immediately than have waited until dinner-time. And, if she had committed the murder, why had she gone about it in the manner likeliest to lead to discovery, openly leaving her guests a few minutes before, and allowing herself to be seen afterwards descending the staircase? Even the veriest neophyte in crime usually displayed some of the caution of self-preservation.

But Caldew was too experienced in criminal investigation to reject a theory merely because it was contrary to experience. There existed presumptions for suspicion of Miss Heredith which at least warranted further inquiry. And, thinking over these presumptions, he arrived at the additional conclusion that the theory of her guilt could also be made to account for the puzzle of the open window in Mrs. Heredith's bedroom. Caldew believed that the open window had some bearing on the crime. His first impression had been that the murderer had entered and escaped by that means. The Virginia creeper to which Weyling had directed attention that morning had strengthened that belief, in spite of Merrington's opinion that the plant would not bear a man's weight. But now it seemed to him that Miss Heredith might have opened the window for the purpose of throwing the revolver into the moat so that it should not be found. He determined to investigate that possibility as soon as he returned to the moat-house.

He reached his destination only to learn that Mr. and Mrs. Weyne had motored over to the moat-house to pay their condolences to the family. He remounted his bicycle and rode back as fast as he could, chagrined to think that he had wasted the best part of an afternoon in a fruitless errand.

It was evening when he reached Heredith again, and rode through the woods towards the moat-house. It looked deserted in the gathering twilight. A fugitive gleam of departing sunshine fell on the bronze and blood-red chrysanthemums in the circular beds, but the shadows were lengthening across the lawn, and the mist from the green waters of the moat was creeping up the stained red walls.

His ring at the front door was answered by the pretty parlourmaid who had been dusting the hall before breakfast. He recognized in Milly Saker a village playmate of nearly twenty years ago, and he recalled that it was she who had told his sister of the difference which had existed between Miss Heredith and her nephew's wife.

Milly greeted the detective with a coquettish smile of recognition.

"How are you?" she said. "You wouldn't look at me this morning. You seemed as if you didn't want to recognize old friends."

Caldew's mind was too preoccupied to meet these rural pleasantries in the same spirit.

"Is Miss Heredith in?" he asked, stepping into the hall.

"I shouldn't be here talking to you if she was," replied the girl pertly. "She's gone to the village in the motorcar to meet Mr. Musard. She's just got a telegram to say he's coming back."

"I thought he was going to France," said Caldew.

"Well, he's not. The telegram says he's not. So Miss Heredith's gone to meet him by the evening train. Tufnell's out too. I don't know where he's poked to, but I shan't cry my eyes out if he never comes back."

"Have Mr. and Mrs. Weyne been here?"

"Yes. They drove over in their car, and saw Miss Heredith and Sir Philip. They weren't here very long."

"Where are Superintendent Merrington and Captain Stanhill?"

"In the library. They come in about an hour ago. The big gentleman has to go back to London to-night—I heard him say so. A good riddance too. He had all the servants in the library this morning, bullying them dreadfully."

"What did he say to you?" asked Caldew, with a smile.

"Nothing," responded the girl promptly, "except what he said early this morning, when he stopped me in the hall here, and put his great ugly hand under my chin, and told me he'd have a talk with me by-and-by. But he didn't get the chance, because I was over in the village all the morning with my mother, who's been ill. But he gave all the other girls such a time that they haven't done talking of it yet. Gwennie Harden, who sleeps with me, says he must have thought one of us murdered Mrs. Heredith, and the cook was so angry with the questions he asked her that she was going to give a month's warning on the spot, but old Tufnell talked her over, saying that it was only done in the way of duty, no personal reflection being intended. Tufnell begged her pardon for what she'd had to put up with, and the cook granted it, and there the matter ended. But they do say that Mrs. Rath—that's the housekeeper—came out of the library looking fit to drop. But Hazel Rath didn't go into the library, although she stayed here last night, and has been with her mother all day. Favouritism, I call it. Why should they put all us servants through our facings, and leave her alone?"

The mention of Hazel Rath's name recalled to Caldew's mind the information his sister had given him about the early association between her and Philip Heredith. But the import of that statement, and the significance of the piece of news Milly Saker had just given him, were not made clear to him until later. At the moment his thoughts were fixed on the idea of testing his new theory about the open window while Miss Heredith was absent. As he turned away, he asked the girl where Sir Philip was.

"He's sitting with Mr. Phil," was the reply.

"I suppose there is nobody upstairs in the left wing?" he added.

"Nobody but the corpse," responded Milly, with a slight shiver. "Miss Heredith's had her bedroom shifted. Last night she slept downstairs, but this morning she gave orders for the white bedroom in the right wing to be prepared for her. I reckon she wants to get as far away from it as possible, and I don't blame her."

Caldew proceeded upstairs, and entered the death-chamber in the silent wing. On his way back from Chidelham he had picked up a round stone, which he now took from his pocket, intending to throw it from the window, and mark the spot where it fell into the moat. He opened the window, and looked out across the garden. The distance to the moat was much farther than he had imagined; so great, indeed, that his own shot at the water fell short by several feet. It was impossible that Miss Heredith could have accomplished such a remarkable feat as to hurl a revolver across the intervening space between the window and the moat. No woman could throw so far and so straight.

This unforeseen obstacle rather disconcerted Caldew at first, but on looking out of the window again it seemed to him, by the lay of the house, that the window of Miss Heredith's bedroom was closer to the moat than the window at which he was standing. As Miss Heredith had transferred her bedroom to the other wing, he decided to go into the room and see if he were right. He still clung to his new idea that the revolver had been thrown into the moat, although his altered view that it might have been thrown from Miss Heredith's window meant the abandonment of his other assumption that the disposal of the revolver by that means accounted for the open window in Mrs. Heredith's bedroom. Caldew realized as he left the room that the question of the open window still remained to be solved. What he did not realize was that he was distorting the facts of the case in order to establish the possibility of his own theory.

The door of the room which Miss Heredith had occupied was ajar. He pushed it open and entered. There was within that deserted and desolate air which a room so quickly takes on when the occupant has vacated it. The heavier furniture and the bed remained to demonstrate the ugliness of utility after the accessories and adjuncts of luxury had been carried away.

The blind was down and the room in partial darkness. Caldew went to the window, raised the blind, and looked out. The distance to the moat was appreciably nearer, compared with the window of the room he had just left, but the distance was still considerable.

As Caldew turned from the window, with the reluctant conviction that he had been nursing an untenable theory, a last ray of sunshine shot through the open window, causing the dust he had raised by his entrance to quiver and gyrate like a host of mad bacilli dancing a jig. The shaft of light, falling athwart the dismantled toilet-table, brought something else into view—a tiny fragment of gold chain dangling from the polished satinwood drawer.

Caldew pulled the drawer open. Inside was a lady's thin gold neck chain, with a bundle of charms and trinkets attached to the end, which had evidently been left behind and forgotten. He glanced at the chain carelessly, and was about to replace it in the drawer, when his eye was arrested by one of the trinkets. It was a small image, not much over an inch in length; a squatting heathen god, with crossed arms and a satyr's face—a wonderful example of savage carving in miniature.

It was not the perfection of the carving or the unusual nature of the ornament which attracted Caldew's attention, but the material, of which it was composed, a clear almost transparent stone, with the faintest possible tinge of green. Holding it in the sunlight, Caldew was able to detect one or two minute black flecks in the stone. There was no doubt about it—the image was of the same peculiar material as the trinket he had seen in the murdered woman's room the previous night.

As he stood there examining the charm, the murmur of voices not far away fell on his ears. Looking cautiously out of the window, he saw Musard and Miss Heredith walk round the side of the house to the garden, deep in earnest conversation. Caldew backed away to an angle where he was not visible from beneath, and watched them closely. Musard was talking, occasionally using an impressive gesture, and Miss Heredith was listening attentively, with a downcast face, and eyes which suggested recent tears. As she passed underneath the window at which he was watching, she raised a handkerchief to her face and sobbed aloud. Caldew wondered to see the proud and reserved mistress of the moat-house show her grief so freely in the presence of Musard, until he remembered what his sister had told him of their supposed early love for each other. And with that thought came another. It must have been Musard, the explorer, the man who had wandered afar in strange lands in search of precious stones, who had brought to the moat-house the peculiar stone of which the missing brooch and the little image had been fashioned.

Acting on the swift impulse to take the image to Miss Heredith and see how she received it, Caldew slipped the chain into his pocket and hurried downstairs. At the bottom of the staircase he was stopped by Tufnell, who had evidently been waiting for him to descend. The usually imperturbable dignity of the butler was for once ruffled, and he looked slightly flushed and dishevelled.

"I have been down to the village looking for you," he said, in a querulous tone. The majesty of the law had not vested Caldew with any dignity in the old butler's eyes. He saw in him only the village urchin of a score of years ago, whose mischievous pranks on the Heredith estate had been a constant source of worry to him.

The detective appreciated the estimation in which the old man held him, and the fact did not tend to lessen his own irritation.

"What did you want me for?" he curtly asked.

"I did not want you, but the gentlemen in the library do. Superintendent Merrington thought you had been a long time away, and he sent me down to the village to look for you. He is anxious to return to London. You will find him in the library."

The butler's cool assumption that it was Merrington's privilege to command, and Caldew's duty to obey, nettled the latter considerably. He felt that Merrington had, in his offensive way, deliberately asserted his official authority in order to humiliate him in his native place. Acting on the impulse of anger he replied:

"I have some things to attend to before I can see him. You can tell him so, if you like."

He walked away towards the hall door, conscious that the butler was standing stationary by the stairs, watching him. When he got outside, he turned his steps towards the garden; but brief as had been the interval since he had seen Musard and Miss Heredith conversing together by the sundial, it had been sufficient to bring the conversation to a conclusion. Miss Heredith was no longer to be seen, and Musard was sauntering along the gravel walk smoking a cigar.

Had they seen him at the window, and broken off their conference in consequence? It looked as if this were so. Miss Heredith must have entered the house by another door, because if she had gone in by the front door he must have encountered her. Caldew would have retraced his steps if Musard had not looked up, and, seeing the detective, waited for him to approach.

Caldew walked towards him, wondering whether Miss Heredith had missed her chain of charms, and had gone upstairs to find it. In that case, he reflected grimly, the position of the previous night was reversed, and this time it was she who was forestalled. It was an ironical situation, truly, but he was to some extent the master of it.

Musard nodded to the detective and proffered his cigarcase. Caldew accepted a cigar and admired the case, which was made of crocodile skin, worked and dressed in a manner altogether new to him. He had never seen anything like it in London tobacconists' shops, and he said so.

"Native manufacture," replied Musard, selecting a fresh cigar. "My Chinese boy shot the crocodile which provided it. It's a rare thing for a Chinese to be a good shot with a modern English rifle, but my boy would carry off anything at Bisley. He never misses. It was lucky for me that he didn't that time, because the brute came along to bag me while I was swimming in a river. Suey, hearing me call, ran out from the tent with my rifle, and shot him from the bank. He got him through the eye—the eye and the throat are the only two vulnerable spots in a crocodile. A bullet will rebound off the head as off a rock."

"Where did this happen?" asked Caldew, in an interested tone. His own knowledge of crocodiles was confined to the fact that he had once seen a small one in a tank at the Zoological Gardens.

"In Zambesi. There are plenty of them there in the rivers and mango swamps. Some hunters stake a dog overnight by the river bank, and the animal gives them warning of the approach of the reptiles by howling with terror. It is rather cruel—to the dog."

"Undoubtedly," said Caldew.

"How are you getting on with your investigations in this case?" continued Musard, abruptly changing the conversation.

Caldew was instantly wary, and stiffened into an attitude of official reserve, wondering why Musard should seek to question him about the murder.

"I am an old friend of the Herediths," continued Musard, as though divining the other's thoughts. "This murder is a very terrible thing for them. I am afraid it may mean Sir Philip's death-blow. He is old and feeble, and the shock, and his son's illness, have had a very bad effect on him. I should have gone to France to-day for the War Office, but I arranged for somebody to go in my place in order to remain with the family in their hour of trial. Have you found out anything which leads you to suppose you are on the track of the murdered?"

"I am afraid I cannot tell you anything about the investigations," replied the detective cautiously. "I am not in charge of the case, you know."

"I understand," rejoined the other, with a nod. "Perhaps I should not have asked you. My anxiety must be my excuse."

He uttered this apology so courteously and pleasantly that Caldew felt momentarily ashamed of his own rigidly official attitude. But his instincts of caution quickly reasserted themselves, and he told himself that in this sinister case it was his business to be on his guard and talk to nobody.

The situation was terminated by the reappearance of Miss Heredith from a door at the side of the house. The detective was a little surprised to see her again, for he had conceived the idea that she had gone indoors to avoid meeting him. She went eagerly to Musard without noticing him.

"Oh, Vincent!" she exclaimed, and the look of relief on her face was unmistakable. "Sir Ralph Horton is just leaving. He says that Phil has passed the crisis, and there is no need for him to stay any longer. Phil still needs great care and attention, but Sir Ralph says it will be quite safe to leave him in Dr. Holmes's hands. There is no fear for his brain, thank God."

"This is good news," said Musard. "Have you told Sir Philip?"

"Not yet. I thought it better to defer it until after dinner. I want you to tell him then."

Miss Heredith turned as though to re-enter the house, but Caldew, who had been hovering a few paces away within earshot of this dialogue, approached her with the gold chain in his hand.

"Excuse me, Miss Heredith," he said. "One of the maids told me that you no longer occupied the room upstairs in the left wing, so I took the liberty of going in there to see if it was possible for the murderer to have escaped by clambering from the window of one room to another, and while I was there I found this chain. It was hanging out of a drawer of the toilet-table near the window, and as it had obviously been forgotten I thought I had better restore it to you."

He held it out to her as he finished speaking, keenly watching her face for some sign of confusion or trepidation. But Miss Heredith received the chain calmly, and thanked him for returning it. Caldew was disappointed at the failure of his test, but he essayed a further shot.

"I noticed a very peculiar little image among the charms on the chain," he said hesitatingly. "I have never seen anything like it before, and I couldn't help wondering where it came from."

It was a clumsy trap, and he realized it, but he was too anxious to achieve his end by more subtle methods. There was nothing in Miss Heredith's calm countenance to suggest that she was alarmed or uneasy at his curiosity. She turned to Musard.

"Mr. Caldew means the strange little image you gave me when you arrived, Vincent. What is it?"

She held out the chain, and the explorer took it in his big brown hand. He separated the image from the other charms with his forefinger, and turned it over carelessly.

"That is a tiki," he said.

The explanation conveyed nothing to Caldew.

"I have never heard the word before," he said. "What is a tiki?"

"It is the Maori word for the creator of man, and is also taken to represent an ancestor," Musard explained. "The Maoris are to some extent ancestor worshippers, and adorn their pahs and temples with large wooden images of immense size, supposed to represent some renowned fighting ancestor. These images are worshipped as gods, and are believed to be visited by the spirits, who ascend to converse with them by the hollow roots of a pohutukawa tree, which descends into the Maori nether regions. The smaller tikis, or, more strictly speaking, hei-tiki, such as this, are carved as representations in miniature of the larger images, and are worn as neck ornaments. They are supposed to render the wearer immune from the wicked designs of evil spirits."

"From what material are they carved?" said Caldew, who had followed this explanation attentively. "I have never seen anything resembling it. It seems as clear and colourless as glass, but it emits a faint greenish lustre, and there are black flecks in it."

"It is nephrite, or Maori greenstone," replied Musard. "London jewellers term it New Zealand jade."

"Surely this stone is not jade?" said Caldew, in some surprise. "I have seen New Zealand jade ornaments in London shops, but they were made from a dull deep greenstone, not a bit like this stone, which is clear as crystal, and has a lustre."

"There are different sorts of jade," replied Musard. "The present craze of Society women is for Chinese pink jade and tourmalin. A good pink jade necklace will readily bring a thousand pounds in Bond Street, and it is going to be the fashionable jewel of the season. New Zealand nephrite has not yet come into popular favour with English ladies, and only the commoner dark green variety, which is frequently spurious, is seen here. This image was made of the rarer kind of pounamu, as the Maoris call it."

"It is very pretty," said Caldew. "Have you any more of it?" He flattered himself that the assumption of carelessness in his tone was not overdone.

"No," replied Musard. "It was the only piece of the rare kind I was ever lucky enough to obtain."

"There was another small piece, Vincent," remarked Miss Heredith. "You brought it about ten years ago. It was the same kind of transparent stone, with black flecks in it."

"I had forgotten. I gave it to Phil, didn't I? What did he do with it?"

"He had it made into a brooch for Hazel Rath, and gave it to her as a birthday gift."