As Caldew returned to the house for his interview with Merrington, the one clear impression on his mind was that the discovery of the owner of the missing brooch was the starting point in the elucidation of the murder.

In the library he found Superintendent Merrington, Captain Stanhill, Inspector Weyling, and Sergeant Lumbe. The sergeant, who looked tired and dirty, was apologetically explaining that his visit to Tibblestone had been fruitless.

"I had my journey for nothing," he was saying in his thick country voice, as Caldew entered. "I had a wild goose chase all over the place, and then it turned out that this chap Mr. Hawkins telephoned about was only a canvasser for In Memoriam cards for fallen soldiers. I come across him at last sitting by the roadside eating his dinner and reading a London picture paper. He looked a doubtful sort of a customer, sure enough, but he was able to prove that he was playing bagatelle in the inn last night at the time the murder was committed."

Superintendent Merrington dismissed this information with a nod, and turned to Caldew.

"Did you interview Mrs. Weyne?" he asked.

"They were not in," was the reply. "I was told they had motored to the moat-house. Did you see them?"

Superintendent Merrington frowned. He had not seen the Weynes, and he had not been informed of their visit. It was another addition to the sum of untoward incidents which had happened to him since his arrival at the moat-house, and he felt very dissatisfied and wrathful.

"I am returning to London by the next train, Caldew," he said, in his authoritative voice. "Official business of importance demands my immediate presence. I will have some inquiries made at Scotland Yard about the people who have been staying here. In the meantime, you had better remain on the spot and continue your inquiries under the Chief Constable."

"I shall be very glad of Detective Caldew's help in unravelling this terrible mystery," Captain Stanhill remarked courteously.

Caldew drew several conclusions from his chief's speech. Merrington was puzzled about the case, but had no intention of taking him into his counsel. Merrington believed that the murderer had got clear away, and, therefore, further local investigation was useless, but he deemed it advisable to keep a Scotland Yard man on the scene to watch for possible developments, because he placed no reliance on the county police. It was apparent that Merrington thought the murderer had come from a distance, and he was going to seek him in London. But he was leaving nothing to chance. He was retaining control of the investigations at both ends in order to monopolize the glory of the capture. If the murderer escaped, Caldew and the county police could be made the scapegoats for public indignation.

But while paying the involuntary tribute of swift anger towards these astute tactics of his departmental chief, Caldew realized with satisfaction that he was in the possession of a piece of valuable information which might upset his calculations.

"There are several people in the district whom it will be advisable to interview," continued Merrington, hastily consulting his notes. "In the first place, you must make another effort to see the Weynes. Mrs. Weyne may be able to give us some valuable information about Mrs. Heredith's earlier life. And I think you should see the station-master of Weydene Junction. The murderer may have walked across country to the junction rather than face the greater risk of subsequent identification by taking the train at one of the village stations on this side of it. And you had better see the housekeeper's daughter and get a statement from her. I do not suppose she knows anything about the crime, but she was here last night, and she had better be seen. She is employed as a milliner at the market town of Stading."

"Do you mean Hazel Rath?" inquired Caldew, in some surprise.

"Yes. She is the daughter of the housekeeper. She stayed here last night with her mother, but left to go back to her employment by the first train this morning."

"There must be some mistake about that. I understand she is still in the house."

"Who told you so?"

"One of the maidservants."

"We had better have the maid in and question her. What is her name?"

"Milly—Milly Saker."

Merrington touched the bell, and told the maidservant who answered it to send in Milly Saker.

The girl came in almost immediately, looking half defiant and half afraid. Merrington glanced at her keenly.

"You're the girl I saw dusting the hall this morning," he said. "Why did you not come in with the other servants to be examined?"

"Because I wasn't here," answered the girl pertly.

"Where were you?"

"Down in the village, at my mother's place."

"Who gave you permission to go?"

"Mrs. Rath, the housekeeper."

"Did you ask her for leave of absence?"

"No. She knew my mother was ill, and she said to me after breakfast, 'Milly, would you like to go and see your mother this morning?' I said, yes, I should, if she could spare me. She told me she could, so I thanked her and went."

Superintendent Merrington and Captain Stanhill exchanged glances. The same thought occurred to both of them. Mrs. Rath, the housekeeper, had assured them that she had sent all the servants to the library to be examined. Merrington turned to the girl again.

"Mrs. Rath's daughter was staying with her last night, wasn't she?"

"Yes."

"Is she still here?"

"Yes."

"Are you quite sure of that?"

"Yes, when I was outside about half an hour ago, I saw her through the window, sitting in her mother's room."

This piece of information conveyed some significance to Merrington's mind which was not apparent to Caldew. He paused for a moment, and then continued abruptly:

"Where were you last night at the time of the murder?"

"Please, sir, I don't know nothing about it," responded the girl with a whimper.

"Control yourself, my good girl," said Captain Stanhill soothingly. "Nobody suggests you had anything to do with it."

For reply, the girl only sobbed loudly. Superintendent Merrington, who had his own methods of soothing frightened females, shook her roughly by the arm.

"Listen to me," he sternly commanded. "Do you want to go to prison?"

"N—o, sir," responded Milly, between a fresh burst of sobs.

"Then you'd better stop that noise and answer my questions, or I'll put you under lock and key till you do. Where were you last night when the murder was committed?"

"I was waiting at table till dessert was served," replied the girl, thoroughly subdued by the overbearing manner of the big man confronting her.

"What did you do when you left the dining-room?"

"I went to the kitchen and was talking to cook for a while."

"And what did you do then?"

"I went up the passage and into the hall to see if dinner was finished. I knew Miss Heredith was anxious to have dinner over early as they were all going out, and I wanted to get dinner cleared away as quickly as I could, because I wanted to go out myself. I saw her leave the room and go towards the front door, but nobody else came out of the dining-room, and I could hear somebody talking. So after waiting a little while, and seeing nobody else come out, I went back towards the kitchen."

"Where were you standing while you were waiting?"

"Just at the corner of the passage leading up from the kitchen."

"You didn't go up stairs at all?"

"No, of course I didn't. 'Tisn't my place to go upstairs."

"Don't be saucy, but answer my questions. Did you hear the scream and the shot?"

"No, I didn't. I was back in the kitchen before then, and the kitchen is right at the back of the house. Cook and me didn't know anything about it till one of the girls came running down and told us about what had happened."

"Did you see anybody except Miss Heredith in the hall or on the staircase of the left wing while you were standing at the end of the passage?"

"Nobody except Miss Rath."

"Do you mean the housekeeper's daughter?"

"Yes."

"When did you see her?"

"As I was standing there waiting for a chance to clear away the dinner things, she come up from the centre passage leading from the housekeeper's rooms, and turned into the hall."

"Where was she going?"

"I don't know. I didn't ask her," replied the girl, who had regained something of her pert assurance.

"Did she see you?"

"No. I was standing at the end of the kitchen passage, which is close to the right wing. The passage she come out of was quite a long way from where I was standing, almost in the centre of the house. She turned the other way."

"She turned to the right, then, as she emerged from the passage, and walked in the direction of the left wing?"

"I don't know where she was going to. All I know is that I saw her turn out of the passage, and walk, as if might be, up the hall in that direction."

"Did you notice her actions?"

"I can't say as I did particular, except that she was walking in the shadow, on the side nearest to the passage she come out of, and seemed to be looking at the dining-room door."

"You are sure it was Hazel Rath?"

"Oh, it was her all right," replied Milly confidently. "I recognized her, as well as the dress she was wearing."

"Was this before or after you saw Miss Heredith leave the dining-room?"

"About ten minutes afterwards."

"Did you mention to anybody that you saw her?"

"I did not," replied the girl, as if the matter were one of supreme indifference to her.

"Why not?"

"I suppose Miss Rath is free to go where she pleases," said the girl airily. "She's privileged. When she used to live here she had the run of the house, just like one of the family. Tain't my business to question her comings and goings."

"Oh, Miss Rath used to live here, did she? How long ago?"

"Till about two years ago, before she went to business."

"And how long did she live here?"

"It must have been a good seven years or more," said Milly, considering. "She come here as a little girl when her mother come as housekeeper. Miss Heredith took a great fancy to her, and she was made quite a pet of the house, and did just what she liked. When she grew up she used to help her mother, and do little things about the house. But she never gave herself airs—I will say that."

"Very well. You may go now."

"Caldew," said Merrington quickly as the door closed behind the girl, "go and find the housekeeper and send her in here. And then keep an eye on her daughter, and do not let her out of your sight, until I send for you. Then bring her in."

When Caldew left the room on his errand, Captain Stanhill turned to Superintendent Merrington with a pained expression on his face.

"Do you suspect—" he commenced.

"I suspect nobody—and everybody," was the prompt reply. "My duty is to find out the facts, and my business is now to ascertain why the housekeeper lied to me about her daughter this morning. She was a fool to try and trick me. There's something underneath all this which I'll sift to the bottom before I leave."

There was a timid tap, and the door opened slowly, revealing the frail black figure of the housekeeper standing hesitatingly on the threshold. Her frightened eyes were directed to Merrington's truculent ones as though impelled by a magnet.

"You—you wished to see me?" she stammered.

"Yes. Come in." Merrington curtly commanded. "Close that door, Lumbe. Sit down, Mrs. Rath, I have a few questions to ask you."

The housekeeper took a seat, with her eyes still fixed on Merrington's face. She looked ill and haggard, but the contour of her worn face, and the outline of her slender figure suggested that she had once possessed beauty and attraction. Merrington, staring at her hard, again had the idea that he had seen her long ago in different conditions and circumstances, but he could not recall where.

"Look here, Mrs. Rath," he commenced abruptly. "I want to know why you lied to me this morning."

"I—I don't know what you mean. I didn't come here to be insulted." The housekeeper uttered these words with a weak attempt at dignity, but her lips went suddenly white.

"Don't put on any fine-lady airs with me, for they won't go down," said Merrington, in a fierce, bullying tone. "You know what I mean very well. You told me this morning, when I asked you, that you had sent in all the servants to be examined. I have just discovered that you did not. There was a girl, Milly Saker, whom I did not see. Why was that?"

It seemed to Captain Stanhill that the tension of the housekeeper's face relaxed, and that a look of relief came into her eyes, as though the question were different from the one she had expected.

"I did not tell you a lie," she replied, in a firmer tone. "I sent in all the servants who were in the house at the time. Milly was not at home."

"Where was she?"

"She went across to the village to see her mother, who is ill."

"With your permission, I presume?"

"Yes."

"Why did you permit her to go?"

"The girl's mother was very ill, and needed her daughter."

"You let her go, although I had told you I wanted to question all the servants?"

"No, it was before you told me that I gave Milly permission to have the morning off," responded Mrs. Rath quietly.

"Is that the true explanation?"

"Yes."

"Is it as true as your other statement?"

"What other statement?"

"The statement you made to me this morning when you assured me your daughter had left this house to return to her employment at Stading?" said Merrington, with a cruel smile. "That wasn't true, you know. How do you describe that untruth? As a temporary aberration of memory, or what?"

The housekeeper looked up with swift, startled eyes, and her thin hand involuntarily clutched the edge of the table in front of her, but she did not speak.

"You lied about that, you know," continued Merrington. "I've found out your daughter has been in the house all day. Why did you tell me a lie? Come, out with it!"

"You are too abrupt, Merrington," said Captain Stanhill, interposing with unexpected firmness. "You have frightened her. Come, Mrs. Rath," he said gently, "can you not give us some explanation as to why you misled us this morning?"

"Because I didn't want my daughter to be drawn into this dreadful thing," she exclaimed wildly. "I suppose it was very foolish of me," she added, in a more composed voice, as though reassured by the kindly look in Captain Stanhill's eyes, "but I really didn't think it mattered. My daughter knew nothing about the murder and as she is highly strung I did not want her to be upset."

"Where was your daughter last night when the murder was committed?" asked Merrington.

"In my room."

"Did either of you hear the scream or the shot?"

"No, my rooms are a long way from the left wing, and we were sitting with the door shut."

"Then when did you learn about the murder?"

"Very soon after it happened. One of the maidservants came and told me."

"And you say that your daughter was with you at the time, and had been with you a considerable time before?"

"Yes."

"I think that will do, Mrs. Rath, I have given you every opportunity, but you still persist in telling falsehoods. Your daughter was seen walking up the hall last night in the direction of the left wing shortly before the murder was committed. The person who saw her was the maid Milly Saker. Was that the real reason why you gave Milly leave of absence to visit her mother this morning—so that she should not tell us what she knew?"

"It is not true," gasped the housekeeper. "My daughter was not out of my rooms last night, I assure you that is the truth."

"I wouldn't believe you on your oath," retorted Merrington. "Lumbe, go and tell Caldew to bring in the girl."