Mr. Flexen did find Mr. Carrington at his office, and Mr. Carrington's first words were:

"Well, have you found the mysterious woman?"

"I've found the mysterious woman, and she's now Mrs. Herbert Manley," said Mr. Flexen.

Mr. Carrington stared at him, then he said softly: "Well, I'm damned!"

"It does explain several things," said Mr. Flexen dryly. "We know now why she was so hard to find—why there was no trace of her relations with Lord Loudwater, no trace of Shepherd's managing the Low Wycombe property among his papers, why there were no pass-books."

Mr. Carrington flushed and said: "The young scoundrel had us on toast all the while."

"Toast is the word," said Mr. Flexen.

"I never did like the beggar. I couldn't stand his infernal manner. But it never occurred to me that he was a bad hat. I merely thought him a pretentious young ass who didn't know his place," said Mr. Carrington.

"I'm not so sure about the ass," said Mr. Flexen.

"No—perhaps not. He certainly brought it off for a time, and shielded her as long as it lasted," said Mr. Carrington slowly.

"She didn't need any shielding," said Mr. Flexen.

"Do you mean to tell me that she didn't murder Loudwater?"

"She did not. You don't murder a man who has just given you twelve thousand pounds," said Mr. Flexen.

"Twelve thousand pounds?" said Mr. Carrington slowly. Then he started from his chair and almost howled: "Are you telling me that Lord Loudwater gave this woman twelve thousand pounds! He never gave any one twelve thousand pounds! He never gave any one a thousand pounds! He never gave any one fifty pounds! He couldn't have done it! Never in his life!"

His voice rose in a fine crescendo.

"Well, perhaps it was hardly a gift," said Mr. Flexen, and he told him
Helena's story.

At the end of it Mr. Carrington said with dogged, sullen conviction: "I don't care, I don't believe it. Lord Loudwater couldn't have done it."

"But there's the letter from her bankers," said Mr. Flexen. "And I suppose you can trace the twelve thousand pounds."

Mr. Carrington started and said sharply: "Why, that must be where the rubber shares went to."

"What rubber shares?" said Mr. Flexen.

"We can't lay our hands on a block of rubber shares Lord Loudwater owned.
The certificate isn't among his scrip—he kept all his scrip at the
Castle—he wouldn't keep it at his bank. Those rubber shares were worth
just about twelve thousand pounds."

"Well, there you are," said Mr. Flexen.

"No, I'm not, I tell you I don't believe in that gift—not even in the circumstances. Lord Loudwater would a thousand times rather have gone on paying the allowance—as little of it as he could. There's something fishy—very fishy—about it, I tell you," said Mr. Carrington vehemently.

"And where did the fishiness come in?" said Mr. Flexen.

Mr. Carrington was silent, frowning. Then he said: "I'll—I'll be hanged if I can see."

Mr. Flexen rose sharply and said: "There's only one point in the affair where it could have come in as far as I can see. I should like to examine Lord Loudwater's letter of instruction to his bankers."

"By George! You've got it," said Mr. Carrington.

"Well, can we get a look at it?" said Mr. Flexen.

"We can. Harrison, the manager, will stretch a point for me. He knows that I'm quite safe. Come along," said Mr. Carrington.

"At this hour? The bank's been closed this two hours," said Flexen.

"He'll be there. It's years since he got away before seven," said Mr.
Carrington confidently.

He told a clerk to telephone to the bank that he was coming. They found a taxicab quickly, drove to the bank, entered it by the side door, and were taken straight to Mr. Harrison.

He made no bones about showing them Lord Loudwater's letter of instructions with regard to the twelve thousand pounds. Mr. Carrington and Mr. Flexen read it together. It was quite short, and ran:

"GENTLEMEN,

"I shall be much obliged by your paying the enclosed cheque from Messrs.
Hanbury and Johnson for £12,046 into the account of Mrs. Helena Truslove.

"Yours faithfully,

"LOUDWATER."

"Rather a curt way of disposing of such a large sum," said Mr. Flexen, taking the letter and going to the window.

"It was the way Lord Loudwater did things," said Mr. Harrison.

"Yes, yes; I know," said Mr. Carrington. "Some things."

They both looked at Mr. Flexen, who was examining the letter through a magnifying glass.

He studied it for a good two minutes, turned to them with a quiet smile of triumph on his face and said: "I've never seen Lord Loudwater's signature. But this is a forgery."

"A forgery?" said the manager sharply, stepping quickly towards Mr.
Flexen with outstretched hand.

"I'm not surprised to hear it," said Mr. Carrington.

"Well, the signature is not written with the natural ease with which a man signs his name," said Mr. Flexen, giving the letter to Mr. Harrison.

Mr. Harrison studied it carefully. Then he pressed a button on his desk and bade the clerk who came bring all the letters they had received from Lord Loudwater during the last three months of his life and bring them quickly.

Then he turned to Mr. Flexen and said stiffly: "I'm bound to say that the signature looks perfectly right to me."

"I've no doubt that it's a good forgery. It was done by a very clever man," said Mr. Flexen.

"A first-class young scoundrel," Mr. Carrington amended.

"We shall soon see," said Mr. Harrison, politely incredulous.

The clerk came with the letters. There were eight of them, all written by Mr. Manley and signed by Lord Loudwater.

The manager compared the signatures of every one of them with the signature in question, using a magnifying glass which lay on his desk.

Then, triumphant in his turn, he said curtly: "It's no forgery."

"Allow me," said Mr. Flexen, and in his turn he compared the signatures, again every one of them.

Then he said: "As I said, it's an uncommonly good forgery. You see that the bodies of the letters are all written with the same pen, a gold-nibbed fountain-pen; the signatures are written with a steel nib. It cuts deeper into the paper, and the ink doesn't flow off it so evenly. The forged signature is written with the same kind of nib as the genuine ones. Also, the bodies of the letters are written in a fountain-pen ink—the 'Swan,' I think. The signatures are written in Stephens' blue-black ink. The forged signature is also written in Stephens' blue-black ink. No error there, you see."

"You seem to know a good deal about these things," said Mr. Harrison, rather tartly.

"Yes. I've been a partner in Punchard's Agency—you know it; we've done some work for you—for the last two years. I didn't need this kind of knowledge for my work in India. I only made a special study of forgery after joining the agency. A private inquiry agency gets such a lot of it," said Mr. Flexen.

"Well, and if there's an error in these details, where is it? It's not in the signature itself," said Mr. Harrison.

"Indeed, it is," said Mr. Flexen. "It's an uncommonly good signature too. The 'Loud' is perfect. But the 'water' gives it away. The forger had evidently practised it a lot. In fact, he wrote the 'Loud' straight off. But the 'water' has no less than five distinct pauses in it—under the microscope, of course—where he paused to think, or perhaps to look at a genuine signature, the endorsement on the cheque very likely."

Mr. Harrison sniffed ever so faintly, and said: "Of course, I've had experience of handwriting experts—not very much, thank goodness!—and you differ among yourselves so. It's any odds that another expert will find those pauses in quite different places from you, or even no pauses at all."

Mr. Flexen laughed gently and said: "Perhaps. But he ought not to."

"There you are. And when it comes to a jury," said Mr. Harrison, and he threw out his hands. "Besides, if you got your experts to agree, you'd have to show a very strong motive."

"Oh, we've got that—we've got that," said Mr. Carrington with conviction.

"Well, of course that will make it easier for you to get the jury to believe your handwriting experts rather than those of the other side," said Mr. Harrison, without any enthusiasm. Then he added, with rather more cheerfulness: "But you never can tell with a jury."

"No; that's true," said Mr. Flexen quickly. "I'm sure we're very much obliged to you for showing us the letter."

There was nothing more to be done at the bank, and having again thanked Mr. Harrison, they took their leave of him. He showed no great cordiality in his leave-taking, he was looking at the matter from the point of view of the bank. The bank preferred to detect forgeries itself—in time.

As they came into the street, Mr. Carrington rubbed his hands together and said in a tone of deep satisfaction: "And now for the warrant."

"Warrant for whom?" said Mr. Flexen in a tone of polite inquiry.

"Manley. The sooner that young scoundrel is in gaol the better I shall feel," said Mr. Carrington.

"So should I," said Mr. Flexen. "But I'm very much afraid that for Mr. Manley it's a far cry to Holloway. We have no case against him whatever—not a scrap of a case that I can see."

"Hang it all! It's as plain as a pikestaff! He's engaged to this woman—this Mrs. Truslove—who has a nice little income. He hears that her income is to be halved; and we know that if an allowance begins by being halved, as likely as not it will be stopped altogether before long. He saw that clearly enough. Then in the very nick of time this cheque comes along. He sends it to the bank with this letter of instructions, and murders Lord Loudwater so that he cannot disavow them. What more of a case do you want?"

"I don't want a better case. I only want some evidence. It's true enough that Mrs. Manley told me that she told Manley that Lord Loudwater proposed to halve her allowance. But where's the evidence that she talked to him about it? She'd deny it if you put her into the witness-box, and you can't put her into the witness-box."

"Husband and wife, by Jove! Oh, the clever young scoundrel!" cried Mr.
Carrington.

"And that halving of the allowance is the beginning of the whole business. Manley had made up his mind to marry a lady with a fixed income—indeed, they were probably already engaged. Loudwater upsets the arrangement. Manley restores the status quo by means of this cheque and the murder of Loudwater. Of course, he hated Loudwater—he admitted as much to me—more than once. But if Loudwater had played fair about that allowance, he'd be alive now. Having established the status quo, Manley promptly marries the lady, and closes the mouth of the only person who can bear witness that the allowance was in danger and he had any motive for murdering Loudwater."

Mr. Carrington ground his teeth and murmured: "The infernal young scoundrel!" Then he broke out violently: "But we're not beaten yet. Now that we know for a fact that he murdered Loudwater and why, there must be some way of getting at him."

"I very much doubt it," said Flexen sadly. "He's an uncommonly able fellow. I don't believe that he's taken a chance. He wears a glove and leaves the knife in the wound, so that there are no bloodstains. And consider the cheque. The bank wouldn't have honoured Loudwater's own cheque, the cheque of a dead man, but the stock-broker's cheque goes through as a matter of course."

"Of course," said Mr. Carrington.

"And he has kept the business so entirely in his own hands. If we had run in any one else, he'd have come forward and sworn that he heard Loudwater snore after Roper had seen that person leave the Castle. I'm beginning to think that he's one of the most able murderers I ever heard of. I certainly never came across one in my own experience who was a patch on him," said Mr. Flexen.

"Don't be in such a hurry to lose hope. There must be some way of getting at him—there must be," said Mr. Carrington obstinately.

"I'm glad to hear it," said Mr. Flexen in a tone of utter scepticism.

They walked on, Mr. Flexen reflecting on Mr. Manley's ability, Mr. Carrington cudgelling his brains for a method of bringing his crime home to him. At the door of his office Mr. Flexen held out his hand.

"Come along in. I've got an idea," said Mr. Carrington.