Pett fell back, staring doubtfully at Brereton's curled lip, and wondering whether to take him seriously or not. And Brereton laughed and went off--to reflect, five minutes later, that this was no laughing matter for Harborough and his daughter, and to plunge again into the maze of thought out of which it was so difficult to drag anything that seemed likely to be helpful.

He interviewed Harborough again before he was taken back to Norcaster, and again he pressed him to speak, and again Harborough gave him a point-blank refusal.

"Not unless it comes to the very worst, sir," he said firmly, "and only then if I see there's no other way--and even then it would only be for my daughter's sake. But it won't come to that! There's three weeks yet--good--and if somebody can't find out the truth in three weeks----"

"Man alive!" exclaimed Brereton. "Your own common-sense ought to tell you that in cases like this three years isn't enough to get at the truth! What can I do in three weeks?"

"There's not only you, sir," replied Harborough. "There's the police--there's the detectives--there's----"

"The police and the detectives are all doing their best to fasten the crime on you!" retorted Brereton. "Of course they are! That's their way.

When they've safely got one man, do you think they're going to look for another? If you won't tell me what you were doing, and where you were that night, well, I'll have to find out for myself."

Harborough gave his counsel a peculiar look which Brereton could not understand.

"Oh, well!" he said. "If _you_ found it out----"

He broke off at that, and would say no more, and Brereton presently left him and walked thoughtfully homeward, reflecting on the prisoner's last words.

"He admits there is something to be found out," he mused. "And by that very admission he implies that it could be found out. Now--how?

Egad!--I'd give something for even the least notion!"

Bent's parlour-maid, opening the door to Brereton, turned to a locked drawer in the old-fashioned clothes-press which stood in Bent's hall, and took from it a registered letter.

"For you, sir," she said, handing it to Brereton. "Came by the noon post, sir. The housekeeper signed for it."

Brereton took the letter into the smoking-room and looked at it with a sudden surmise that it might have something to do with the matter which was uppermost in his thoughts. He had had no expectation of any registered letter, no idea of anything that could cause any correspondent of his to send him any communication by registered post.

There was no possibility of recognizing the handwriting of the sender, for there was no handwriting to recognize: the address was typewritten.

And the postmark was London.

Brereton carefully cut open the flap of the envelope and drew out the enclosure--a square sheet of typewriting paper folded about a thin wad of Bank of England notes. He detached these at once and glanced quickly at them. There were six of them: all new and crisp--and each was for a hundred and fifty pounds.

Brereton laid this money aside and opened the letter. This, too, was typewritten: a mere glance at its termination showed that it was anonymous. He sat down at Bent's desk and carefully read it through.

There was no address: there was nothing beyond the postmark on the envelope to show where the letter came from; there was absolutely nothing in the contents to give any clue to the sender. But the wording was clear and plain.

"MR. GIFFORD BRERETON,--Having learnt from the newspapers that you are acting as counsel for John Harborough, charged with the murder of a man named Kitely at Highmarket, I send you the enclosed 900 to be used in furthering Harborough's defence. You will use it precisely as you think fit. You are not to spare it nor any endeavour to prove Harborough's innocence--which is known to the sender. Whenever further funds are needed, all you need do is to insert an advertis.e.m.e.nt in the personal column of _The Times_ newspaper in these words: _Highmarket Exchequer needs replenishing_, with your initials added. Allow me to suggest that you should at once offer a reward of 500 to whoever gives information which will lead to the capture and conviction of the real murderer or murderers. If this offer fails to bring information speedily, double it. I repeat that no pains must be spared in this matter, and that money to any amount is no object.

The sender of this letter will keep well informed of the progress of events as narrated in the newspapers, to which you will please to afford all proper information."

Brereton read this extraordinary communication through three times; then he replaced letter and bank-notes in the envelope, put the envelope in an inner pocket, left the house, and walking across to the Northrop villa, asked to see Avice Harborough.

Avice came to him in Mrs. Northrop's drawing-room, and Brereton glancing keenly at her as she entered saw that she was looking worn and pale. He put the letter into her hands with a mere word.

"Your father has a powerful friend--somewhere," he said.

To his astonishment the girl showed no very great surprise. She started a little at the sight of the money; she flushed at one or two expressions in the letter. But she read the letter through without comment and handed it back to him with a look of inquiry.

"You don't seem surprised!" said Brereton.

"There has always been so much mystery to me about my father that I'm not surprised," she replied. "No!--I'm just thankful! For this man--whoever he is--says that my father's innocence is known to him. And that's--just think what it means--to me!"

"Why doesn't he come forward and prove it, then?" demanded Brereton.

Avice shook her head.

"He--they--want it to be proved without that," she answered. "But--don't you think that if all else fails the man who wrote this would come forward? Oh, surely!"

Brereton stood silently looking at her for a full minute. From the first time of meeting with her he had felt strangely and strongly attracted to his client's daughter, and as he looked at her now he began to realize that he was perhaps more deeply interested in her than he knew.

"It's all the most extraordinary mystery--this about your father--that ever I came across!" he exclaimed suddenly. Then he looked still more closely at her. "You've been worrying!" he said impetuously. "Don't! I beg you not to. I'll move heaven and earth--because I, personally, am absolutely convinced of your father's innocence. And--here's powerful help."

"You'll do what's suggested here?" she asked.

"Certainly! It's a capital idea," he answered. "I'd have done it myself if I'd been a rich man--but I'm not. Cheer up, now!--we're getting on splendidly. Look here--ask Mrs. Northrop to let you come out with me.

We'll go to the solicitor--together--and see about that reward at once."

As they presently walked down to the town Brereton gave Avice another of his critical looks of inspection.

"You're feeling better," he said in his somewhat brusque fashion. "Is it this bit of good news?"

"That--and the sense of doing something," she answered. "If I wasn't looking well when you came in just now, it was because this inaction is bad for me. I want to do something!--something to help. If I could only be stirring--moving about. You understand?"

"Quite!" responded Brereton. "And there is something you can do. I saw you on a bicycle the other day. Why not give up your teaching for a while, and scour the country round about, trying to get hold of some news about your father's movements that night? That he won't tell us anything himself is no reason why we shouldn't find out something for ourselves. He must have been somewhere--someone must have seen him! Why not begin some investigation?--you know the district. How does that strike you?"

"I should be only too thankful," she said. "And I'll do it. The Northrops are very kind--they'll understand, and they'll let me off.

I'll begin at once--tomorrow. I'll hunt every village between the sea and the hills!"

"Good!" said Brereton. "Some work of that sort, and this reward--ah, we shall come out all right, you'll see."

"I don't know what we should have done if it hadn't been for you!" said Avice. "But--we shan't forget. My father is a strange man, Mr. Brereton, but he's not the sort of man he's believed to be by these Highmarket people--and he's grateful to you--as you'll see."

"But I must do something to merit his grat.i.tude first, you know,"

replied Brereton. "Come!--I've done next to nothing as yet. But we'll make a fresh start with this reward--if your father's solicitor approves."

The solicitor did approve--strongly. And he opened his eyes to their widest extent when he read the anonymous letter and saw the bank-notes.

"Your father," he observed to Avice, "is the most mysterious man I ever heard of! The Kitely mystery, in my opinion, is nothing to the Harborough mystery. Do you really mean to tell me that you haven't an idea of what all this means?"

"Not an idea!" replied Avice. "Not the ghost of one."

"Well--we'll get these posters and handbills out, anyway, Mr. Brereton,"

said the solicitor. "Five hundred pounds is a good figure. Lord bless you!--some of these Highmarket folk would sell their mothers for half that! The whole population will be turned into amateur detectives. Now let's draft the exact wording, and then we'll see the printer."

Next day the bill-poster placarded Highmarket with the reward bills, and distributed them broadcast in shops and offices, and one of the first persons to lay hands on one was Mallalieu & Cotherstone's clerk, Herbert Stoner.