THERE was a knock at the door, and Lester entered. He and Bradshaw had been thrown together a good deal. Staying, as they did, at the same inn, they met frequently, and each man recog­nized qualities in the other which tended to establish confidence and friendship.

"Poison yourself," was the American's welcome, as he pushed the whisky-decanter toward his new visitor.

Hobson, unaware that Lester was acquainted with his theft of Edith's second letter, looked up at the young doctor with the ingratiating smile of one who would have bygones be bygones. He was quickly undeceived.

"Well," said Lester, addressing him with scant courtesy, "may I ask if you have posted that other letter of Miss Holt's, or have you appropriated to your own use the draft contained in it?"

For once, Hobson's inscrutable countenance be­trayed emotion. He went deathly pale, and the excuse that was trembling on his lips gave place to the truthfulness of honest indignation. "I don't think I have deserved that," he said with something of natural dignity. "Miss Holt's letter, with the money it held, has been posted safely enough, and I am bound to say, in justice to the young lady, that what she wrote clears her at least from one suspicion. Now, sir, technically, I have committed a crime which might have grave consequences for me. Though you really have no evidence against me, I am not going to attempt any concealment. I have only taken reasonable measures to unravel a mys­terious murder, and I am willing to put it to Mr. Bradshaw, here, whether in the interests of justice I did not act rightly."

"Why, say," remarked Bradshaw, "I don't know a thing about the matter yet. You say you have committed a crime. I am open to believe that about anybody. Don't be discouraged, Hobson. At your age, it can't be the first crime you have committed. And I am dead sure it won't be the last."

The answer came from Lester, who found the American's lazy cynicism a little jarring. "In­spector Hobson's crime is simply this," he said curtly: "he has been tampering with the post-office in order to get hold of Miss Holt's private correspond­ence."

"I don't think we ought to blame him for that," said Bradshaw, dispassionately. "A man does not become a detective, anyway, unless he has the in­stincts of a horse thief. Sit down, Hobson," he went on, as the official, really hurt, half rose. "I don't mean that as personal — in fact, I am trying to justify you. See here, Dr. Lester, if you face things fairly and squarely, you must realize that no detective work is possible without what you and I would call underhanded methods. After all, noth­ing of the sort will injure an innocent person in the long run; and your British police have the reputa­tion of being reasonably honest, though," he admitted, when Hobson's countenance cleared a little, "I am not much of a believer in miracles myself. Look cheerful, Hobson, and have another drink. Dr. Lester is going to forgive you."

William Lincoln Bradshaw suggested the con­sumption of alcohol with appalling frequency, but as his own habit was to take rather less than a teaspoonful on each occasion, he, at least, suffered no ill effects from his pressing hospitality.

"I want no forgiveness from anybody," said the detective, sulkily. "I am only doing my duty. Miss Holt may be as innocent as you or I, but you can't dispute that Lord Arncliffe was murdered, Mr. Aingier nearly murdered, and possibly other crimes committed which these more serious ones were meant to cloak. I don't profess to be a Sher­lock Holmes. My system is to give my attention to the person who benefits most from a crime. And I have never drawn blank yet."

"Well, now," said Bradshaw to Lester, "I was just telling this unerring sleuth-hound of some peculiarities which had struck me in the conduct of that blatant Britisher, Warren. Don't wink the nap off your eyelids at me, friend Hobson. Just at present I propose to make my calculations on the basis that Dr. Lester is a square man, and if you don't like it you can do the other thing, for the proposition is my own. Now, Lester, I have also been telling our friend here about that poacher fellow whose extraordinary access of wealth we have both noticed. And I have further drawn his atten­tion to the fact that Harry Warren is drinking a great deal more than any one takes out of mere devotion to liquor. He gives one the impression of a man so harassed that he is endeavoring all the time to escape from his own vicinity. I am inclined to attribute all this to the workings of a trouble­some imp called conscience, which we read about in fairy tales. I have also made some considerable study of Arncliffe Hall lately, and I notice there is a light in one of the rooms half through the night — conscience again. People who live in a Sleepy Hollow like this go to bed early, in the hope of dream­ing they are alive. If we could take a peep into that room we might see something to enlighten us."

"What room is it?" asked Hobson.

"The room just over the library, where old Ain­gier got soaked on the cabeza."

Bradshaw had spent his early days amid that delightful society which infests the valley of the Rio Grande. When talking of deeds of violence, he had a habit of introducing, here and there, a word of Spanish, which is, after all, the natural language of assassination.

"Oh, but it is no good bothering about that," protested the detective. "That is simply the private sitting-room of Mrs. Warren, the housekeeper."

"So I supposed. But what special cares has Mrs. Warren to keep her up so late? I first noticed this burning of the midnight oil on the night of the attack on Aingier. As you know, Dr. Lester, I waited until you decided that your patient was out of immediate danger; and then we came back here together, nearly at daylight. It was reasonable enough that Mrs. Warren should remain awake on that occasion, and I should have thought nothing further of the matter, had not the same thing been repeated night after night. I watched round about the Hall — partly because this business has interested me, and partly because I have been doing a little detective business on my own account. I surmise this much — that Mrs. Warren waits up to talk with this hopeful son of hers. And I am inclined to think that a little knowledge of the situa­tion on our part would produce quite a lot of in­formation."

"I don't like spying," objected Lester, a note of decision in his voice.

"Neither do I," retorted Bradshaw, "but I should like still less for that winsome young girl to be charged with murder, as Hobson proposes. Any­way, it is not your funeral. I am only telling you a plan of my own."

"If there is anything I can do to help Miss Holt," began Lester, eagerly.

"Ah, you see that side of it, do you? If you really want to do violence to your high-toned feel­ings, you might just go and mix some liquor with the wealthy gentleman they call Leigh, and shadow him home, too. I wouldn't be at all surprised if that skunk Warren dropped into the game before you are through."

Bradshaw looked at his watch. "Half-past ten," he continued. "You have half an hour in which to cultivate Mr. Robert Leigh. Now go away, boy, and leave Hobson and myself to elaborate our low­down plans."

Lester, half offended, yet conscious that Brad­shaw was in the right, went down-stairs. But there was no sign of the poacher. He returned, offered to help the others, but was sent to bed.

Bradshaw and the detective, taciturn men by nature but rendered talkative by the necessity to hide their thoughts, remained silent for a long time, considering the position. There was really little to go upon. A light in a window at an unusual hour might have a dozen adequate explanations. The mere events which had happened at the Hall were enough to account for the sleeplessness of an elderly woman to whom Arncliffe Hall had practically represented the world for so many years.

But Hobson, finding himself completely at a loss, was ready to follow the slightest clue. Bradshaw, like Lester, had declined from the beginning to admit even the possibility of Edith's guilt; but he realized nevertheless that there was negative evidence in existence against her which, though it might not place her life in peril, yet might embitter it irrevo­cably. And, as far as lay in his power, he resolved to save her.

"I have been studying the geography pretty care­fully," he explained to his companion when the light­ing of a new cigar aroused him from a reverie. "There is a tree which looks conveniently into that window. A boy who is accustomed to birds'-nest­ing might fix himself up comfortably."

"Perhaps," interrupted Hobson, acidly, "you could suggest something suitable to a man of forty-five who suffers from rheumatism?"

"I haven't any rheumatism," replied the Ameri­can, cheerfully, "and I guess I can climb that tree. I will tell you a fairy tale about what I see after­ward. Things ought to be reasonably quiet at the Hall about eleven; and if we reach there half an hour later, that will do. Smoke!" and he handed over a Havana from his waistcoat pocket, "but don't talk to me; I want to figure things some more."

And so they sat again in silence, until presently Bradshaw looked at his watch and closed it with a snap.

"Ten past eleven," he said: "Twenty minutes' walk to the Hall. Come along, partner, we had better make a move."

They went down-stairs softly. "Jolly Jim" Jones was just clearing away the empty tankards of his village customers.

"Going out to breathe for awhile, boss," said Bradshaw. "Don't worry about me; I have my key."

"All right, sir. You won't take a drop of my special to keep the cold out before you go?"

"No, thank you, I have people dependent on me in the United States. Good night."

The country lane was utterly deserted. It was silent enough to ears not tuned to the myriad voices of the night — the chirp of the cricket, the rustling of a dry leaf as an errant breeze kissed it, the trem­bling of a branch touched by a weazel gliding forth on foray, the sudden soft whir of wings as an owl swept down on its prey, the stirring of the under­growth in the Park by the unseen animals which abounded in its fastnesses.

And so the two advanced, as noiselessly as pos­sible, until there came a fitful gleam between the trees. It was the light for which they had come to look; the light which had shone night after night — telling what story? Perhaps only the story of a mother's anguish — the anguish of a mother whose son was coming home with dimmed eyes and falter­ing steps. All this Bradshaw thought of, but he thought of Edith Holt too, and went on.

A short cut through the woods and they found themselves beneath the lighted window. There was an oak which spread its branches close to the room, thirty feet above. Without a needless word, Bradshaw drew his companion close to the trunk and climbed upon his shoulders to reach the first stout limb of the tree.

Once within the boughs, the American climbed up like any school-boy, and settled himself on the branch nearest to the window, perching precariously at the extreme limit of safety. He found that the window was closed; therefore, nothing could be heard, yet the scene within the room offered ample material for speculation when he came to ponder on it afterwards.

Harry Warren, looking utterly cowed, was sitting in an arm-chair, while his mother stormed up and down the room like a very fury. There was, through all her anger, the repression characteristic of the woman. It was no exaggeration to say that she stormed, yet her voice was never raised; strain his ears as he might, Bradshaw could hear no syllable of the conversation. He waited until he grew cramped and until Hobson beneath was hoarsely impatient, and still Mrs. Warren talked with fiery animation, but always, it seemed, with her natural restraint.

Then, at last, she quitted the room. Her son, who had sat dejected and nervous during the harangue, jumped up alertly. He pulled open drawer after drawer of the desk and searched them so fran­tically, with such bungling haste, that he did not notice his mother's return. She entered, with a certain stealth, and stood behind him, impassive as ever. Warren apparently found what he sought and thrust it guiltily into his pocket. And so the incident might have rested a mere matter between Harry Warren and his mother, if Bradshaw had not coughed. It was a little cough, altogether too slight to be noticed, one would have thought.

Mrs. Warren laid a caressing hand on her son's shoulder, seeming to reason with him. Then she stooped to one of the drawers he had ransacked, and, turning swiftly, fired point-blank through the glass at the figure she could see dimly outlined in the branches of the oak.