Saul Arthur Mann came back to England full of his news, and found Frank at the little Jermyn Street hotel where he had installed himself, and Frank listened without interruption to the story of the letter.

"Of course," the little fellow went on, "I went straight over to Montreux. The note heading was not on the paper, but I had no difficulty, by comparing the qualities of papers used at the various hotels, in discovering that it was written from the Palace. The head waiter knew this Rex Holland, who had been a frequent visitor, had always tipped very liberally, and lived in something like style. He could not describe his patron, except that he was a young man with a very languid manner who had arrived the previous morning from Holland and had immediately inquired for Frank Merrill."

"From Holland! Are you sure it was the morning? I have a particular reason for asking," asked Frank quickly.

"No, it was not in the morning, now you mention it. It was in the evening. He left again the following morning by the northern train."

"How did he find my address?" asked Frank.

"Obviously from the visitors' list. The waiter on duty in the writing room remembered having seen him consulting the newspaper. Now, my boy, you have to be perfectly candid with me. What do you know about Rex Holland?"

Frank opened his case, took out a cigarette, and lit it before he replied.

"I know what everybody knows about him," he said, with a hint of bitterness in his voice, "and something which nobody knows but me."

"But, my dear fellow," said Saul Arthur Mann, laying his hand on the other's shoulder, "surely you realize how important it is for you that you should tell me all you know."

Frank shook his head.

"The time is not come," he said, and he would make no further statement.

But on another matter he was emphatic.

"By heaven, Mann, I am not going to stand by and see May ruin her life. There's something sinister in this influence which Jasper is exercising over her. You have seen it for yourself."

Saul Arthur nodded.

"I can't understand what it is," he confessed. "Of course Jasper is not a bad-looking fellow. He has perfect manners and is a charming companion. You don't think--"

"That he is winning on his merits?" Frank shook his head. "No, indeed, I do not. It is difficult for me to discuss my private affairs, and you know how reluctant I am to do so, but you are also aware of what I think of May. I was hoping that we should go back to the place where we left off, and, although she is kindness itself, this girl who is more to me than anything or anybody in the world, and who was prepared to marry me, and would have married me but for Jasper's machinations, was almost cold."

He was walking up and down the room, and now halted in his stride and spread out his arms despairingly.

"What am I to do? I cannot lose her. I cannot!"

There was a fierceness in his tone which revealed the depth of his feeling, and Saul Arthur Mann understood.

"I think it is too soon to say you have lost her, Frank," he said.

He had conceived a genuine liking for Frank Merrill, and the period of tribulation through which the young man had passed had heightened the respect in which he held him.

"We shall see light in dark places before we go much farther," he said. "There is something behind this crime, Frank, which I don't understand, but which I am certain is no mystery to you. I am sure that you are shielding somebody, for what reason I am not in a position to tell, but I will get to the bottom of it."

No event in the interesting life of this little man, who had spent his years in the accumulation of facts, had so distressed and piqued him as the murder of John Minute. The case had ended where the trial had left it.

Crawley, who might have offered a new aspect to the tragedy, had disappeared as completely as though the earth had swallowed him. The most strenuous efforts which the official police had made, added to the investigations which Saul Arthur Mann had conducted independently, had failed to trace the fugitive ex-sergeant of police. Obviously, he was not to be confounded with Rex Holland. He was a distinct personality working possibly in collusion, but there the association ended.

It had occurred to the investigator that possibly Crawley had accompanied Rex Holland in his flight, but the most careful inquiries which he had pursued at Montreux were fruitless in this respect as in all others.

To add to his bewilderment, investigations nearer at home were constantly bringing him across the track of Frank Merrill. It was as though fate had conspired to show the boy in the blackest light. Frank had been acting as secretary to his uncle, and then Jasper Cole had suddenly appeared upon the scene from nowhere in particular. The suggestion had been made somewhat vaguely that he had come from "abroad," and it was certain that he arrived as a result of long negotiations which John Minute himself had conducted. They were negotiations which involved months of correspondence, no letter of which either from one or the other had Frank seen.

While the trial was pending, the little man collected quite a volume of information, both from Frank and the girl, but nothing had been quite as inexplicable as this intrusion of Jasper Cole upon the scene, or the extraordinary mystery which John Minute had made of his engagement.

He had written and posted all the letters to Jasper himself, and had apparently received the replies, which he had burned, at some other address of which Frank was ignorant.

Jasper had come, and then one day there had been a quarrel, not between the two young men, but between Frank and his uncle. It was a singularly bitter quarrel, and again Frank refused to discuss the cause. He left the impression upon Saul Arthur's mind that he had to some extent been responsible. And here was another fact which puzzled "The Man Who Knew." Sergeant Smith, as he was then, had been to some extent responsible. It was Frank who had introduced the sergeant to Eastbourne and brought him to his uncle. But this was only one aspect of the mystery. There were others as obscure.

Saul Arthur Mann went back to his bureau, and for the twentieth time gathered the considerable dossiers he had accumulated relating to the case and to the characters, and went through them systematically and carefully.

He left his office near midnight, but at nine o'clock the next morning was on his way to Eastbourne. Constable Wiseman was, by good fortune, enjoying a day's holiday, and was at work in his kitchen garden when Mr. Mann's car pulled up before the cottage. Wiseman received his visitor importantly, for, though the constable's prestige was regarded in official circles as having diminished as a result of the trial, it was felt by the villagers that their policeman, if he had not solved the mystery of John Minute's death, had at least gone a long way to its solution.

In the spotless room which was half kitchen and half sitting room, with its red-tiled floor covered by bright matting, Mrs. Wiseman produced a well-dusted Windsor chair, which she placed at Saul Arthur Mann's disposal before she politely vanished. In a very few words the investigator stated his errand, and Constable Wiseman listened in noncommittal silence. When his visitor had finished, he shook his head.

"The only thing about the sergeant I know," he said, "I have already told the chief constable who sat in that very chair," he explained. "He was always a bit of a mystery--the sergeant, I mean. When he was 'tanked,' if I may use the expression, he would tell you stories by the hour, but when he was sober you couldn't get a word out of him. His daughter only lived with him for about a fortnight."

"His daughter!" said Mr. Mann quickly.

"He had a daughter, as I've already notified my superiors," said Constable Wiseman gravely. "Rather a pretty girl. I never saw much of her............