It was so late that Ludgate Circus was deserted except for a ramshackle cab with a drunken driver pouring forth a hoarse story of a mean fare to a sleepy policeman leaning against a lamp post. The sight of two gentlemen on foot when all 'buses had stopped running for the night raised fleeting hopes in the cabman's pessimistic breast, and changed the flow of his narrative into a strident appeal for hire, based on the plea, which he called on the policeman to support, that he hadn't turned a wheel that night, and amplified with a profanity which only the friendliest understanding with the policeman could have permitted him to pour forth without fear of consequences.

He intimated his readiness to drive them anywhere between the Angel on one side of London and the Elephant on the other for three bob, or, being a bit of a sport, would toss them to make it five bob or nothing. The boundaries, he explained in a husky parenthesis, were fixed not so much by his own refusal to travel farther afield as by his horse's unwillingness to go into the blasted suburbs. As his importunities passed unregarded he damned them both with the terrible earnestness of his class, and rumbled back into his dislocated story with the languid policeman.

Colwyn kept his car in a garage off the Bridge Street archway. Thither they proceeded, and waited while the car was got ready for the roads by a shock-headed man who broke the stillness of the night with prodigious yawns, and then stood blinking like an owl as he leaned against the yard gates watching the detective backing the car down the declivity of the passage into Bridge Street. Before they had reached it, he banged the gates behind him with another tremendous yawn, and went back to his interrupted slumber in the interior of a limousine.

It was a fine night for motoring. There was a late moon, and the earlier rain had laid the dust and left the roads in good condition. Colwyn cautiously threaded the crooked tangle of narrow streets and sharp corners between Blackfriars and Victoria, but as the narrow streets opened into broader ways he increased the speed of his high-powered car, and by the time London was left behind for the quiet meadows and autumn-scented woods they were racing along the white country roads at a pace which caused the roadside avenues of trees to slide past them like twin files of soldiers on the double.

Mile after mile slipped away in silence. Beyond an occasional direction of route by Phil there was no conversation between the two men in the car. Phil sat back looking straight in front of him, apparently absorbed in thought, and the car occupied Colwyn's attention. When they reached the heights above Heredith, Phil pointed to the green flats beneath and the old house in a shroud of mist.

"That is the moat-house," he said. "The carriage drive is from the village side." And with that brief indication that they were nearing their journey's end he once more settled back into silence.

Colwyn brought the car down from the rise into the sleeping village, and a few minutes later he was driving up the winding carriage way between the rows of drooping trees. On the other side of the woods the moat-house came into view. The moonlight gleamed on the high-pitched red roof, and drenched the garden in whiteness, but the mist which rose from the waters of the moat swathed the walls of the house like a cerement. The moon, crouching behind the umbrageous trees of the park, cast a heavy shadow on the lawn, like a giant's hand menacing the home of murder.

Late as the hour was, Tufnell was up awaiting their arrival, with a light supper and wine set ready in a small room off the library. Phil had telephoned from Colwyn's rooms to say that he was returning with the detective, and the butler, as he helped them off with their coats, said that rumours of a railway accident had reached the moat-house, causing Miss Heredith much anxiety until she received the telephone message.

Colwyn and Phil sat down to supper, with the butler in assiduous attendance. The meal was a slight and silent one. Phil kept a host's courteous eye on his guest's needs, but showed no inclination for conversation, and Colwyn was not the man to talk for talking's sake. When they had finished Phil asked the butler which room Mr. Colwyn was to occupy.

"Miss Heredith has had the room next to Sir Philip's prepared, sir."

"No doubt you are tired, Mr. Colwyn, and would like to retire," Phil said.

"Thank you, I should. I travelled from Scotland last night, and had very little sleep."

"In that case you will be glad to go to bed at once. I will show you to your room," said the young man, rising from the table.

"Please do not bother," replied Colwyn, noting the worn air and white face of the other. "You look done up yourself."

"Miss Heredith was anxious that you should retire as soon as you could, sir, so as to get as much rest as possible after your journey," put in the butler, with the officious solicitude of an old servant.

"Then I shall leave you in Tufnell's care," said Phil, holding out his hand as he said good night.

He went out of the room, and Colwyn was left with the old butler.

"Is it your wish to retire now?" the latter inquired.

"I shall be glad to do so, if you will show me to my bedroom."

The butler bowed gravely, and escorted Colwyn upstairs to his bedroom.

"This is your room, sir. I hope you will be comfortable."

"I feel sure that I shall," replied Colwyn, with a glance round the large handsome apartment.

"Your dressing-room opens off it, sir."

"Thank you. Good night."

"Good night, sir." The butler turned hesitatingly towards the door, as though he wished for some excuse to linger, but could think of nothing to justify such a course. He walked out of the room into the passage, and then turned suddenly, the light through the open doorway falling on his sharpened old features and watchful eyes.

"What is it? Do you wish to speak to me?" said Colwyn, with his pleasant smile.

A look of perplexity and doubt passed over the butler's face as he paused irresolutely in the doorway.

"I merely wished to ask, sir, if there is anything else I can get for you before I go."

His face had resumed its wonted impassivity, and the words came promptly, but Colwyn knew it was not the answer he had intended to make.

"I want nothing further," he said.

The butler bowed, and hurried away. Colwyn stood for a few moments pondering over the incident. Then he went to bed and slept soundly.

He was awakened in the morning by the twittering of birds in the ivy outside his window. The mist from the moat crept up the glasslike steam, but through it he caught glimpses of a dappled autumn sky, and in the distance a bright green hill, with a trail of white clouds floating over the feathery trees on the summit. As he watched the rapid play of light and shade on the hill, he wondered why the moat-house had been built on the damp unwholesome flat lands instead of on the breezy height.

When he descended later, he found Tufnell awaiting him in the hall to conduct him to the breakfast table. In the breakfast-room Sir Philip, Miss Heredith, and Vincent Musard were assembled. The baronet greeted Colwyn with his gentle unfailing courtesy, and Musard shook hands with him heartily. The fact that Phil had brought him to the moat-house was in itself sufficient to ensure a gracious reception from Miss Heredith, but as soon as she saw Colwyn she felt impelled to like him on his own account. It was not the repose and simplicity of his manners, or his freedom from the professional airs of ostentatious notoriety which attracted her, though these things had their weight with a woman like Miss Heredith, by conveying the comforting assurance that her guest was at least a gentleman. There was more than that. She was immediately conscious of that charm of personality which drew the liking of most people who came in contact with Colwyn. In the strong clear-cut face of the great criminologist, there was the abiding quality of sympathy with the sufferings which spring from human passions and the tragedy of life. But, if his serenity of expression suggested that he had not allowed his own disillusionment with life to embitter his outlook or narrow his vision, his glance also suggested a clear penetration of human motives which it would be unwise to try to blind. Miss Heredith instinctively realized that Colwyn was one of those rare human beings who are to be both feared and trusted.

"You will not see my nephew until later," she explained to him as they sat down to breakfast. "He is far from strong yet, and he has had so little sleep since his illness that I am always glad when he is able to rest quietly. I looked in his room a few minutes ago and he was sleeping soundly, so I darkened the room and left him to sleep on."

Colwyn expressed his sympathy. His quick intelligence, gauging his new surroundings and the members of the household, had instantly divined the sterling qualities, the oddities, and class prejudices which made up the strong individuality of the mistress of the moat-house. He saw, for all her dignified front, that she was suffering from a shock which had shaken her to her inmost being, and he respected her for bearing herself so bravely under it.

The breakfast progressed in the leisurely way of the English morning meal. The tragedy which had darkened the peaceful life of the household nearly a fortnight before was not mentioned. Colwyn appreciated the tact of his hostess in keeping the conversation to conventional channels, leaving it for him to introduce the object of his visit in his own time. Only at the conclusion of the meal, as Miss Heredith was leaving the apartment, did she tell him that she hoped he would let her know if there was anything he required or wished her to do. He thanked her, and said there was nothing just then. Later, it would be necessary for him to go over the house, under her guidance, if she could spare the time. She replied that she could do so after lunch if that would be suitable, and went away. Sir Philip followed her, and Colwyn and Musard were left alone.

"Shall we have a cigar in the garden?" said Musard. He wished to know more of the man of whom he had heard so much by repute, and he believed that tobacco promoted sociability. He also desired to find out whether Colwyn's presence at the moat-house meant that Phil had succeeded in impressing him with his own belief in the innocence of Hazel Rath.

Colwyn willingly agreed. He realized the difficulties of the task ahead of him, and he welcomed the opportunity of hearing all he could about the murder from somebody who knew all the circumstances. Phil's personal knowledge of the facts did not extend beyond the point where he had fallen unconscious in the bedroom, and a talk with Musard offered the best available substitute for his own lack of first-hand impressions.

The garden basked in the warmth of a mellow autumn sunshine which had dispersed the morning mist. In the air was the scent of late flowers and the murmurs of bees; the bright eyes of blackbirds and robins peeped out from the ornamental yews, and the peacocks trailed their plumes over the sparkling emerald lawns. But Colwyn and Musard had no thought of the beauty of the morning or the charm of the old-world garden as they paced across the lawn. It was Musard who broached the subject which was engrossing their minds.

"It was very good of you to come down here, Mr. Colwyn. Your visit is a great relief to Miss Heredith."

"Does Miss Heredith share her nephew's belief in Miss Rath's innocence?"

"I would not go so far as to say that, though I think his own earnestness has impressed her with the hope that some mistake has been made. But her chief concern is her nephew's health, and she is anxious, above all things, to remove his mental worry and unrest. The mere fact that you have undertaken to make further inquiries into the case will do much to ease his mind."

"I will do what I can. My principal difficulty is to pick up the threads of the case. It is some time since the murder was committed, and the attendant circumstances which might have helped me in the beginning no longer exist. It is like groping for the entrance to a maze which has been covered over by the growths of time."

"Do you yourself believe it possible that Hazel Rath is innocent?"

"I have come here to investigate the case. The police account for the girl's possession of Captain Nepcote's revolver, with which Mrs. Heredith was shot, by the theory that she obtained it from the gun-room of the moat-house shortly before the murder. There is work for me to do both here and in London, in clearing up this point. It is so important that I cannot understand the attitude of Detective Caldew in dismissing it as a matter of no consequence. If Hazel Rath were convicted with that question unsettled, she would be condemned on insufficient evidence. It is for this reason I have taken her interests into my hands. But, apart from this point, I am bound to say that the case against her strikes me as a very strong one."

"Yet it is quite certain that Phil Heredith believes her innocent," remarked Musard thoughtfully.

"Belief is an intangible thing. In any case, his belief is not shared by you."

"How do you know that?"

"You would have said so."

"Well, I will go so far as to say that Hazel Rath is a most unlikely person to commit murder."

"Murder is an unlikely crime. There is no brand of Cain to reveal the modern murderer. Finger-prints are a surer means of identification. This unhappy girl may be the victim of one of those combinations of sinister events which sometimes occur in crime, but I do not intend to form an opinion about that until I know more about the case. For that reason I shall be glad if you will give me your account of everything that happened on the night of the murder. Philip Heredith's story is incomplete, and I wish to hear all the facts."

Musard nodded, and related the particulars with an attention to detail which left little to be desired. His version filled in the gaps of Phil's imperfect narrative, and enabled the detective to visualize the murder with greater mental distinctness. The two stories agreed in their essential particulars, but they varied in some degree in detail. Colwyn, however, was well aware that different witnesses never exactly agree in their impressions of the same event. Phil had made only an incidental reference to the dinner-table conversation about jewels, and Colwyn was not previously aware that the story of the ruby ring had occupied twenty minutes in the telling.

"How did you come to tell the story?" he asked.

"Some of the ladies were admiring my ring, and Phil suggested that they should hear the story of its discovery. I had just finished when the scream rang out from upstairs, followed by the shot."

"How long was the interval between the scream and the shot?"

"Only a few seconds," replied Musard. "Some of us started to go upstairs as soon as we heard it, but the shot followed before we reached the door of the dining-room."

Colwyn reflected that this estimate differed from Phil Heredith's, who had thought that nearly half a minute elapsed between the scream and the shot. But he knew that a correct estimate of the lapse of time is even rarer than an accurate computation of distance.

Musard knew nothing about two aspects of the case on which Colwyn desired to gain light. He had seen nothing of the target shooting in the gun-room the day before the murder, but he thought it quite possible that Captain Nepcote's revolver might have lain there unnoticed until the following night, because the men of the house party were a poor shooting lot who were not likely to use the gun-room much. He had heard the head gamekeeper say that there had been no shooting parties, and Tufnell had told him that only one or two of the men had brought guns with them. Neither was Musard aware whether there existed the motive of wronged virtue or slighted affection to arouse a girl like Hazel Rath to commit such a terrible crime. He had always thought her a sweet and modest girl, but he had seen too much of the world to place much reliance on externals, and he had had very few opportunities of observing whether there had been anything in the nature of a love affair between her and Philip. His own view was that whatever feeling existed was on the girl's side only.

"If there had been love passages between them, Phil's conscience would not have allowed him to be quite so certain of her innocence," added Musard. "I told him of her arrest, and there can be no doubt that he thinks the police have made a hideous mistake in arresting her. Detective Caldew refused to admit the possibility of mistake, but Phil shuts his eyes to everything that tells against the girl, including her mother's unpleasant past."

"Did Miss Heredith know anything of her housekeeper's past?"

"No. Mrs. Rath, as she calls herself, came to Heredith many years ago, took a small cottage, and tried to support her daughter and herself by giving lessons in music and French. She would have starved if it had not been for Miss Heredith, who helped her and her little girl, tried to get the mother some pupils, and finally took her into the moat-house as housekeeper. Mrs. Rath disappeared from the place after her daughter's arrest, when the police had decided that it was not necessary to detain her, leaving a note behind her for Miss Heredith to say that she couldn't face her after all that had happened."

Colwyn did not speak immediately. He was examining the row of upper windows which looked down on the garden in which they were standing.

"Is that the window of the room in which Mrs. Heredith was murdered?" he asked, pointing to the first one.

"Yes. It is high for a first-floor window, but there is a fall in the ground on this side of the house."

Colwyn tested the strength of the Virginia creeper which grew up the wall almost to the window, and then bent down to examine the grass and earth underneath.

"Caldew thought at first that the murderer escaped from the window, but Merrington did not agree with him," said Musard.

If the remark was intended to extract an expression of opinion from Colwyn it failed in effect, for he remained silent. He had regained his feet, and was looking up at the window again.

"Where is the door which opens on the back staircase of this wing?" he said, at length.

"At the extreme end. You cannot see it from here. It opens on the back of the house."

"According to the newspaper reports of the case, the door is always kept locked. Is that correct?"

"As a general rule it is. But it was found unlocked before dinner on the night the murder was committed."

"I was not informed of this before."

"Phil was not aware of it, and Detective Caldew attached so little importance to it when I told him after the murder that I should not have thought it worth mentioning if you had not asked me. Caldew's point of view was that the door had been left unlocked, accidentally, by one of the servants, which is quite possible. I understand both detectives agree that it had nothing to do with the murder, because the door was locked by the butler, who discovered it unlocked, fully an hour before the murder was committed. If Hazel Rath had attempted to escape that way she would have been caught in a cul-de-sac, for we rushed upstairs from the dining-room immediately we heard the scream."

"Did you search the back staircase?"

"Almost immediately. It was empty."

"And there is no doubt that the door at the bottom was locked?"

"None whatever—one of the young men tried it."

"What time did the butler make his discovery?"

"Shortly before dinner. I do not know the exact time."

"Thank you. Now, if you will excuse me, I should like to see the room Mrs. Heredith occupied. Is it empty?"

"Yes. The wing has been unoccupied since the night of the murder. Shall I show you the way up?"

"It will not be necessary. I know the way, and I shall be there some time."

"In that case I will leave you till lunch-time," responded Musard, as he walked away.

Colwyn did not go upstairs immediately. He took a solitary walk in the woods, thinking over everything that Musard had told him. Then he returned to the house and mounted the staircase to the left wing. His first act was to make a thorough examination of the unused back staircase at the end of the corridor. Then he entered the bedroom Mrs. Heredith had occupied.

The room had the forlorn appearance of disuse. The bed had been partly stripped, and the tall-backed chairs, in prim linen covers, looked like seated ghosts with arms a-kimbo. Colwyn's first act was to draw the heavy window curtains and open the window. He then commenced an examination of the room in the morning sunlight.

His examination was long and thorough, but it brought nothing to light which added to his knowledge of the events of the murder. The time went on, and he was still engrossed in his scrutiny when the door opened and Phil entered the room.