This man never moved or stirred to greet anybody; but the sight of him in the outer room seemed to move Peter Wain to his first nervous query.

  ‘Is anybody with the chief?’ he asked.

  ‘Don’t get rattled, Peter,’ chuckled his uncle. ‘Wilton the secretary is with him, and I hope that’s enough for anybody. I don’t believe Wilton ever sleeps for watching Merton. He is better than twenty bodyguards. And he’s quick and quiet as an Indian.’

  ‘Well, you ought to know,’ said his nephew, laughing. ‘I remember the Red Indian tricks you used to teach me when I was a boy and liked to read Red Indian stories. But in my Red Indian stories Red Indians seemed always to have the worst of it.’

  ‘They didn’t in real life,’ said the old frontiersman grimly.

  ‘Indeed?’ inquired the bland Mr Blake. ‘I should have thought they could do very little against our firearms.’

  ‘I’ve seen an Indian stand under a hundred guns with nothing but a little scalping-knife and kill a white man standing on the top of a fort,’ said Crake.

  ‘Why, what did he do with it?’ asked the other.

  ‘Threw it,’ replied Crake, ‘threw it in a flash before a shot could be fired. I don’t know where he learnt the trick.’

  ‘Well, I hope you didn’t learn it,’ said his nephew, laughing.

  ‘It seems to me,’ said Father Brown, thoughtfully, ‘that the story might have a moral.’

  While they were speaking Mr Wilton, the secretary, had come out of the inner room and stood waiting; a pale, fair-haired man with a square chin and steady eyes with a look like a dog’s; it was not difficult to believe that he had the single — eye of a watchdog.

  He only said, ‘Mr Merton can see you in about ten minutes,’ but it served for a signal to break up the gossiping group. Old Crake said he must be off, and his nephew went out with him and his legal companion, leaving Father Brown for the moment alone with his secretary; for the negroid giant at the other end of the room could hardly be felt as if he were human or alive; he sat so motionless with his broad back to them, staring towards the inner room.

  ‘Arrangements rather elaborate here, I’m afraid,’ said the secretary. ‘You’ve probably heard all about this Daniel Doom, and why it isn’t safe to leave the boss very much alone.’

  ‘But he is alone just now, isn’t he?’ said Father Brown.

  The secretary looked at him with grave, grey eyes. ‘For fifteen minutes,’ he said. ‘For fifteen minutes out of the twenty-four hours. That is all the real solitude he has; and that he insists on, for a pretty remarkable reason.’

  ‘And what is the reason?’ inquired the visitor. Wilton, the secretary, continued his steady gaze, but his mouth, that had been merely grave, became grim.

  ‘The Coptic Cup,’ he said. ‘Perhaps you’ve forgotten the Coptic Cup; but he hasn’t forgotten that or anything else. He doesn’t trust any of us about the Coptic Cup. It’s locked up somewhere and somehow in that room so that only he can find it; and he won’t take it out till we’re all out of the way. So we have to risk that quarter of an hour while he sits and worships it; I reckon it’s the only worshipping he does. Not that there’s any risk really; for I’ve turned all this place into a trap I don’t believe the devil himself could get into — or at any rate, get out of. If this infernal Daniel Doom pays us a visit, he’ll stay to dinner and a good bit later, by God! I sit here on hot bricks for the fifteen minutes, and the instant I heard a shot or a sound of struggle I’d press this button and an electrocuting current would run in a ring round that garden wall, so that it ‘ud be death to cross or climb it. Of course, there couldn’t be a shot, for this is the only way in; and the only window he sits at is away up on the top of a tower as smooth as a greasy pole. But, anyhow, we’re all armed here, of course; and if Doom did get into that room he’d be dead before he got out.’

  Father Brown was blinking at the carpet in a brown study. Then he said suddenly, with something like a jerk: ‘I hope you won’t mind my mentioning it, but a kind of a notion came into my head just this minute. It’s about you.’

  ‘Indeed,’ remarked Wilton, ‘and what about me?’

  ‘I think you are a man of one idea,’ said Father Brown, ‘and you will forgive me for saying that it seems to be even more the idea of catching Daniel Doom than of defending Brander Merton.’

  Wilton started a little and continued to stare at his companion; then very slowly his grim mouth took on a rather curious smile. ‘How did you — what makes you think that?’ he asked.

  ‘You said that if you heard a shot you could instantly electrocute the escaping enemy,’ remarked the priest. ‘I suppose it occurred to you that the shot might be fatal to your employer before the shock was fatal to his foe. I don’t mean that you wouldn’t protect Mr Merton if you could, but it seems to come rather second in your thoughts. The arrangements are very elaborate, as you say, and you seem to have elaborated them. But they seem even more designed to catch a murderer than to save a man.’

  ‘Father Brown,’ said the secretary, who had recovered his quiet tone, ‘you’re very smart, but there’s something more to you than smartness. Somehow you’re the sort of man to whom one wants to tell the truth; and besides, you’ll probably hear it, anyhow, for in one way it’s a joke against me already. They all say I’m a monomaniac about running down this big crook, and perhaps I am. But I’ll tell you one thing that none of them know. My full name is John Wilton Border.’ Father Brown nodded as if he were completely enlightened, but the other went on.

  ‘This fellow who calls himself Doom killed my father and uncle and ruined my mother. When Merton wanted a secretary I took the job, because I thought that where the cup was the criminal might sooner or later be. But I didn’t know who the criminal was and could only wait for him; and I meant to serve Merton faithfully.’

  ‘I understand,’ said Father Brown gently; ‘and, by the way, isn’t it time that we attended on him?’

  ‘Why, yes,’ answered Wilton, again starting a little out of his brooding so that the priest concluded that his vindictive mania had again absorbed him for a moment. ‘Go in now by all means.’

  Father Brown walked straight into the inner room. No sound of greetings followed, but only a dead silence; and a moment after the priest reappeared in the doorway.

  At the same moment the silent bodyguard sitting near the door moved suddenly; and it was as if a huge piece of furniture had come to life. It seemed as though something in the very attitude of the priest had been a signal; for his head was against the light from the inner window and his face was in shadow.

  ‘I suppose you will press that button,’ he said with a sort of sigh.

  Wilton seemed to awake from his savage brooding with a bound and leapt up with a catch in his voice.

  ‘There was no shot,’ he cried.

  ‘Well,’ said Father Brown, ‘it depends what you mean by a shot.’

  Wilton rushed forward, and they plunged into the inner room together. It was a comparatively small room and simply though elegantly furnished. Opposite to them one wide window stood open, over-looking the garden and the wooded plain. Close up against the window stood a chair and a small table, as if the captive desired as much air and light as was allowed him during his brief luxury of loneliness.

  On the little table under the window stood the Coptic Cup; its owner had evidently been looking at it in the best light. It was well worth looking at, for that white and brilliant daylight turned its precious stones to many-coloured flames so that it might have been a model of the Holy Grail. It was well worth looking at; but Brander Merton was not looking at it. For his head had fallen back over his chair, his mane of white hair hanging towards the floor, and his spike of grizzled beard thrust up towards the ceiling, and out of his throat stood a long, brown painted arrow with red feathers at the other end.

  ‘A silent shot,’ said Father Brown, in a low voice; ‘I was just wondering about those new inventions for silencing firearms. But this is a very old invention, and quite as silent.’

  Then, after a moment, he added: ‘I’m afraid he is dead. What are you going to do?’

  The pale secretary roused himself with abrupt resolution. ‘I’m going to press that button, of course,’ he said, ‘and if that doesn’t do for Daniel Doom, I’m going to hunt him through the world till I find him.’

  ‘Take care it doesn’t do for any of our friends,’ observed Father Brown; ‘they can hardly be far off; we’d better call them.’

  ‘That lot know all about the wall,’ answered Wilton. ‘None of them will try to climb it, unless one of them ... is in a great hurry.’

  Father Brown went to the window by which the arrow had evidently entered and looked out. The garden, with its flat flower-beds, lay far below like a delicately coloured map of the world. The whole vista seemed so vast and empty, the tower seemed set so far up in the sky that as he stared out a strange phrase came back to his memory.

  ‘A bolt from the blue,’ he said. ‘What was that somebody said about a bolt from the blue and death coming out of the sky? Look how far away everything looks; it seems extraordinary that an arrow could come so far, unless it were an arrow from heaven.’

  Wilton had returned, but did not reply, and the priest went on as in soliloquy. ‘One thinks of aviation. We must ask young Wain ... about aviation.’

  ‘There’s a lot of it round here,’ said the secretary.

  ‘Case of very old or very new weapons,’ observed Father Brown. ‘Some would be quite familiar to his old uncle, I suppose; we must ask him about arrows. This looks rather like a Red Indian arrow. I don’t know where the Red Indian shot it from; but you remember the story the old man told. I said it had a moral.’

  ‘If it had a moral,’ said Wilton warmly, ‘it was only that a real Red Indian might shoot a thing farther than you’d fancy. It’s nonsense your suggesting a parallel.’

  ‘I don’t think you’ve got the moral quite right,’ said Father Brown.

  Although the little priest appeared to melt into the millions of New York next day, without any apparent attempt to be anything but a number in a numbered street, he was, in fact, unobtrusively busy for the next fortnight with the commission that had been given him, for he was filled with profound fear about a possible miscarriage of justice. Without having any particular air of singling them out from his other new acquaintances, he found it easy to fall into talk with the two or three men recently involved in the mystery; and with old Hickory Crake especially he had a curious and interesting conversation. It took place on a seat in Central Park, where the veteran sat with his bony hands and hatchet face resting on the oddly-shaped head of a walking-stick of dark red wood, possibly modelled on a tomahawk.

  ‘Well, it may be a long shot,’ he said, wagging his head, ‘but I wouldn’t advise you to be too positive about how far an Indian arrow could go. I’ve known some bow-shots that seemed to go straighter than any bullets, and hit the mark to amazement, considering how long they had been travelling. Of course, you practically never hear now of a Red Indian with a bow and arrows, still less of a Red Indian hanging about here. But if by any chance there were one of the old Indian marksmen, with one of the old Indian bows, hiding in those trees hundreds of yards beyond the Merton outer wall — why, then I wouldn’t put it past the noble savage to be able to send an arrow over the wall and into the top window of Merton’s house; no, nor into Merton, either. I’ve seen things quite as wonderful as that done in the old days.’

  ‘No doubt,’ said the priest, ‘you have done things quite as wonderful, as well as seen them.’

  Old Crake chuckled, and then said gruffly: ‘Oh, that’s all ancient history.’

  ‘Some people have a way of studying ancient history,’ the priest said. ‘I suppose we may take it there is nothing in your old record to make people talk unpleasantly about this affair.’

  ‘What do you mean?’ demanded Crake, his eyes shifting sharply for the first time, in his red, wooden face, that was rather like the head of a tomahawk.

  ‘Well, since you were so well acquainted with all the arts and crafts of the Redskin—’ began Father Brown slowly.

  Crake had had a hunched and almost shrunken appearance as he sat with his chin propped on its queer-shaped crutch. But the next instant he stood erect in the path like a fighting bravo with the crutch clutched like a cudgel.

  ‘What?’ he cried — in something like a raucous screech— ‘what the hell! Are you standing up to me to tell me I might happen to have murdered my own brother-in-law?’

  From a dozen seats dotted about the path people looked to-wards the disputants, as they stood facing each other in the middle of the path, the bald-headed energetic little man brandishing his outlandish stick like a club, and the black, dumpy figure of the little cleric looking at him without moving a muscle, save for his hinging eyelids. For a moment it looked as if the black, dumpy figure would be knocked on the head, and laid out with true Red Indian promptitude and dispatch; and the large form of an Irish policeman could be seen heaving up in the distance and bearing down on the group. But the priest only said, quite placidly, like one answering an ordinary query:

  ‘I have formed certain conclusions about it, but I do not think I will mention them till I make my report.’

  Whether under the influence of the footsteps of the policeman or of the eyes of the priest, old Hickory tucked his stick under his arm and put his hat on again, grunting. The priest bade him a placid good morning, and passed in an unhurried fashion out of the park, making his way to the lounge of the hotel where he knew that young Wain was to be found. The young man sprang up with a greeting; he looked even more haggard and harassed than before, as if some worry were eating him away; and the priest had a suspicion that his young friend had recently been engaged, with only too conspicuous success, in evading the last Amendment to the American Constitution. But at the first word about his hobby or favourite science he was vigilant and concentrated enough. For Father Brown had asked, in an idle and conversational fashion, whether much flying was done in that district, and had told how he had at first mistaken Mr Merton’s circular wall for an aerodrome.

  ‘It’s a wonder you didn’t see any while we were there,’ answered Captain Wain. ‘Sometimes they’re as thick as flies; that open plain is a great place for them, and I shouldn’t wonder if it were the chief breeding-ground, so to speak, for my sort of birds in the future. I’ve flown a good deal there myself, of course, and I know most of the fellows about here who flew in the war; but there are a whole lot of people taking to it out there now whom I never heard of in my life. I suppose it will be like motoring soon, and every man in the States will have one.’

  ‘Being endowed by his Creator,’ said Father Brown with a smile, ‘with the right to life, liberty, and the pursuit of motoring — not to mention aviation. So I suppose we may take it that one strange aeroplane passing over that house, at certain times, wouldn’t be noticed much.’

  ‘No,’ replied the young man; ‘I don’t suppose it would.’

  ‘Or even if the man were known,’ went on the other, ‘I suppose he might get hold of a machine that wouldn’t be recognized as his. If you, for instance, flew in the ordinary way, Mr Merton and his friends might recognize the rig-out, perhaps; but you might pass pretty near that window on a different pattern of plane, or whatever you call it; near enough for practical purposes.’

  ‘Well, yes,’ began the young man, almost automatically, and then ceased, and remained staring at the cleric with an open mouth and eyes standing out of his head.

  ‘My God!’ he said, in a low voice; ‘my God!’

  Then he rose from the lounge seat, pale and shaking from head to foot and still staring at the priest.

  ‘Are you mad?’ he said; ‘are you raving mad?’

  There was a silence and then he spoke again in a swift hissing fashion. ‘You positively come here to suggest—’

  ‘No; only to collect suggestions,’ said Father Brown, rising. ‘I may have formed some conclusions provisionally, but I had better reserve them for the present.’

  And then saluting the other with the same stiff civility, he passed out of the hotel to continue his curious peregrinations.

  By the dusk of that day they had led him down the dingy streets and steps that straggled and tumbled towards the river in the oldest and most irregular part of the city. Immediately under the coloured lantern that marked the entrance to a rather low Chinese restaurant he encountered a figure he had seen before, though by no means presenting itself to the eye as he had seen it.

  Mr Norman Drage still confronted the world grimly behind his great goggles, which seemed somehow to cover his face like a dark musk of glass. But except for the goggles, his appearance had undergone a strange transformation in the month that had elapsed since the murder. He had then, as Father Brown had noted, been dressed up to the nines — up to that point, indeed, where there begins to be too fine a distinction between the dandy and the dummy outside a tailor’s shop. But now all those externals were mysteriously altered for the worse; as if the tailor’s dummy had been turned into a scarecrow. His top hat still existed, but it was battered and shabby; his clothes were dilapidated; his watch-chain and minor ornaments were gone. Father Brown, however, addressed him as if they had met yesterday, and made no demur to sitting down with him on a bench in the cheap eating-house whither he was bound. It was not he, however, who began the conversation.

  ‘Well?’ growled Drage, ‘and have you succeeded in avenging your holy and sainted millionaire? We know all millionaires are holy and sainted; you can find it all in the papers next day, about how they lived by the light of the Family Bible they read at their mother’s knee. Gee! if they’d only read out some of the things there are in the Family Bible, the mother might have been startled some. And the millionaire, too, I reckon. The old Book’s full of a lot of grand fierce old notions they don’t grow nowadays; sort of wisdom of the Stone Age and buried under the Pyramids. Suppose somebody had flung old man Merton from the top of that tower of his, and let him be eaten by dogs at the bottom, it would be no worse than what happened to Jezebel. Wasn’t Agag hacked into little pieces, for all he went walking delicately? Merton walked delicately all his life, damn him — until he got too delicate to walk at all. But the shaft of the Lord found him out, as it might have done in the old Book, and struck him dead on the top of his tower to be a spectacle to the people.