Mr Calhoun Kidd was a very young gentleman with a very old face, a face dried up with its own eagerness, framed in blue-black hair and a black butterfly tie.  He was the emissary in England of the colossal American daily called the Western Sun -also humorously described as the “Rising Sunset”.  This was in allusion to a great journalistic declaration (attributed to Mr Kidd himself) that “he guessed the sun would rise in the west yet, if American citizens did a bit more hustling.”  Those, however, who mock American journalism from the standpoint of somewhat mellower traditions forget a certain paradox which partly redeems it.  For while the journalism of the States permits a pantomimic vulgarity long past anything English, it also shows a real excitement about the most earnest mental problems, of which English papers are innocent, or rather incapable.  The Sun was full of the most solemn matters treated in the most farcical way.  William James figured there as well as “Weary Willie,” and pragmatists alternated with pugilists in the long procession of its portraits.

Thus, when a very unobtrusive Oxford man named John Boulnois wrote in a very unreadable review called the Natural Philosophy Quarterly a series of articles on alleged weak points in Darwinian evolution, it fluttered no corner of the English papers; though Boulnois’s theory (which was that of a comparatively stationary universe visited occasionally by convulsions of change) had some rather faddy fashionableness at Oxford, and got so far as to be named “Catastrophism”.  But many American papers seized on the challenge as a great event; and the Sun threw the shadow of Mr Boulnois quite gigantically across its pages.  By the paradox already noted, articles of valuable intelligence and enthusiasm were presented with headlines apparently written by an illiterate maniac, headlines such as “Darwin Chews Dirt; Critic Boulnois says He Jumps the Shocks” -or “Keep Catastrophic, says Thinker Boulnois.”  And Mr Calhoun Kidd, of the Western Sun, was bidden to take his butterfly tie and lugubrious visage down to the little house outside Oxford where Thinker Boulnois lived in happy ignorance of such a title.

That fated philosopher had consented, in a somewhat dazed manner, to receive the interviewer, and had named the hour of nine that evening.  The last of a summer sunset clung about Cumnor and the low wooded hills; the romantic Yankee was both doubtful of his road and inquisitive about his surroundings; and seeing the door of a genuine feudal old-country inn, The Champion Arms, standing open, he went in to make inquiries.

In the bar parlour he rang the bell, and had to wait some little time for a reply to it.  The only other person present was a lean man with close red hair and loose, horsey-looking clothes, who was drinking very bad whisky, but smoking a very good cigar.  The whisky, of course, was the choice brand of The Champion Arms; the cigar he had probably brought with him from London.  Nothing could be more different than his cynical negligence from the dapper dryness of the young American; but something in his pencil and open notebook, and perhaps in the expression of his alert blue eye, caused Kidd to guess, correctly, that he was a brother journalist.

“Could you do me the favour,” asked Kidd, with the courtesy of his nation, “of directing me to the Grey Cottage, where Mr Boulnois lives, as I understand?”

“It’s a few yards down the road,” said the red-haired man, removing his cigar; “I shall be passing it myself in a minute, but I’m going on to Pendragon Park to try and see the fun.”

“What is Pendragon Park?” asked Calhoun Kidd.

“Sir Claude Champion’s place -haven’t you come down for that, too?” asked the other pressman, looking up.  “You’re a journalist, aren’t you?”

“I have come to see Mr Boulnois,” said Kidd.

“I’ve come to see Mrs Boulnois,” replied the other.  “But I shan’t catch her at home.”  And he laughed rather unpleasantly.

“Are you interested in Catastrophism?” asked the wondering Yankee.

“I’m interested in catastrophes; and there are going to be some,” replied his companion gloomily.  “Mine’s a filthy trade, and I never pretend it isn’t.”

With that he spat on the floor; yet somehow in the very act and instant one could realize that the man had been brought up as a gentleman.

The American pressman considered him with more attention.  His face was pale and dissipated, with the promise of formidable passions yet to be loosed; but it was a clever and sensitive face; his clothes were coarse and careless, but he had a good seal ring on one of his long, thin fingers.  His name, which came out in the course of talk, was James Dalroy; he was the son of a bankrupt Irish landlord, and attached to a pink paper which he heartily despised, called Smart Society, in the capacity of reporter and of something painfully like a spy.

Smart Society, I regret to say, felt none of that interest in Boulnois on Darwin which was such a credit to the head and hearts of the Western Sun.  Dalroy had come down, it seemed, to snuff up the scent of a scandal which might very well end in the Divorce Court, but which was at present hovering between Grey Cottage and Pendragon Park.

Sir Claude Champion was known to the readers of the Western Sun as well as Mr Boulnois.  So were the Pope and the Derby Winner; but the idea of their intimate acquaintanceship would have struck Kidd as equally incongruous.  He had heard of (and written about, nay, falsely pretended to know) Sir Claude Champion, as “one of the brightest and wealthiest of England’s Upper Ten”; as the great sportsman who raced yachts round the world; as the great traveller who wrote books about the Himalayas, as the politician who swept constituencies with a startling sort of Tory Democracy, and as the great dabbler in art, music, literature, and, above all, acting.  Sir Claude was really rather magnificent in other than American eyes.  There was something of the Renascence Prince about his omnivorous culture and restless publicity -, he was not only a great amateur, but an ardent one.  There was in him none of that antiquarian frivolity that we convey by the word “dilettante”.

That faultless falcon profile with purple-black Italian eye, which had been snap-shotted so often both for Smart Society and the Western Sun, gave everyone the impression of a man eaten by ambition as by a fire, or even a disease.  But though Kidd knew a great deal about Sir Claude -a great deal more, in fact, than there was to know -it would never have crossed his wildest dreams to connect so showy an aristocrat with the newly-unearthed founder of Catastrophism, or to guess that Sir Claude Champion and John Boulnois could be intimate friends.  Such, according to Dalroy’s account, was nevertheless the fact.  The two had hunted in couples at school and college, and, though their social destinies had been very different (for Champion was a great landlord and almost a millionaire, while Boulnois was a poor scholar and, until just lately, an unknown one), they still kept in very close touch with each other.  Indeed, Boulnois’s cottage stood just outside the gates of Pendragon Park.

But whether the two men could be friends much longer was becoming a dark and ugly question.  A year or two before, Boulnois had married a beautiful and not unsuccessful actress, to whom he was devoted in his own shy and ponderous style; and the proximity of the household to Champion’s had given that flighty celebrity opportunities for behaving in a way that could not but cause painful and rather base excitement.  Sir Claude had carried the arts of publicity to perfection; and he seemed to take a crazy pleasure in being equally ostentatious in an intrigue that could do him no sort of honour.  Footmen from Pendragon were perpetually leaving bouquets for Mrs Boulnois; carriages and motor-cars were perpetually calling at the cottage for Mrs Boulnois; balls and masquerades perpetually filled the grounds in which the baronet paraded Mrs Boulnois, like the Queen of Love and Beauty at a tournament.  That very evening, marked by Mr Kidd for the exposition of Catastrophism, had been marked by Sir Claude Champion for an open-air rendering of Romeo and Juliet, in which he was to play Romeo to a Juliet it was needless to name.

“I don’t think it can go on without a smash,” said the young man with red hair, getting up and shaking himself.  “Old Boulnois may be squared -or he may be square.  But if he’s square he’s thick -what you might call cubic.  But I don’t believe it’s possible.”

“He is a man of grand intellectual powers,” said Calhoun Kidd in a deep voice.

“Yes,” answered Dalroy; “but even a man of grand intellectual powers can’t be such a blighted fool as all that.  Must you be going on?  I shall be following myself in a minute or two.”

But Calhoun Kidd, having finished a milk and soda, betook himself smartly up the road towards the Grey Cottage, leaving his cynical informant to his whisky and tobacco.  The last of the daylight had faded; the skies were of a dark, green-grey, like slate, studded here and there with a star, but lighter on the left side of the sky, with the promise of a rising moon.

The Grey Cottage, which stood entrenched, as it were, in a square of stiff, high thorn-hedges, was so close under the pines and palisades of the Park that Kidd at first mistook it for the Park Lodge.  Finding the name on the narrow wooden gate, however, and seeing by his watch that the hour of the “Thinker’s” appointment had just struck, he went in and knocked at the front door.  Inside the garden hedge, he could see that the house, though unpretentious enough, was larger and more luxurious than it looked at first, and was quite a different kind of place from a porter’s lodge.  A dog-kennel and a beehive stood outside, like symbols of old English country-life; the moon was rising behind a plantation of prosperous pear trees, the dog that came out of the kennel was reverend-looking and reluctant to bark; and the plain, elderly man-servant who opened the door was brief but dignified.

“Mr Boulnois asked me to offer his apologies, sir,” he said, “but he has been obliged to go out suddenly.”

“But see here, I had an appointment,” said the interviewer, with a rising voice.  “Do you know where he went to?”

“To Pendragon Park, sir,” said the servant, rather sombrely, and began to close the door.

Kidd started a little.

“Did he go with Mrs -with the rest of the party?” he asked rather vaguely.

“No, sir,” said the man shortly; “he stayed behind, and then went out alone.”  And he shut the door, brutally, but with an air of duty not done.

The American, that curious compound of impudence and sensitiveness, was annoyed.  He felt a strong desire to hustle them all along a bit and teach them business habits; the hoary old dog and the grizzled, heavy-faced old butler with his prehistoric shirt-front, and the drowsy old moon, and above all the scatter-brained old philosopher who couldn’t keep an appointment.

“If that’s the way he goes on he deserves to lose his wife’s purest devotion,” said Mr Calhoun Kidd.  “But perhaps he’s gone over to make a row.  In that case I reckon a man from the Western Sun will be on the spot.”

And turning the corner by the open lodge-gates, he set off, stumping up the long avenue of black pine-woods that pointed in abrupt perspective towards the inner gardens of Pendragon Park.  The trees were as black and orderly as plumes upon a hearse; there were still a few stars.  He was a man with more literary than direct natural associations; the word “Ravenswood” came into his head repeatedly.  It was partly the raven colour of the pine-woods; but partly also an indescribable atmosphere almost described in Scott’s great tragedy; the smell of something that died in the eighteenth century; the smell of dank gardens and broken urns, of wrongs that will never now be righted; of something that is none the less incurably sad because it is strangely unreal.

More than once, as he went up that strange, black road of tragic artifice, he stopped, startled, thinking he heard steps in front of him.  He could see nothing in front but the twin sombre walls of pine and the wedge of starlit sky above them.  At first he thought he must have fancied it or been mocked by a mere echo of his own tramp.  But as he went on he was more and more inclined to conclude, with the remains of his reason, that there really were other feet upon the road.  He thought hazily of ghosts; and was surprised how swiftly he could see the image of an appropriate and local ghost, one with a face as white as Pierrot’s, but patched with black.  The apex of the triangle of dark-blue sky was growing brighter and bluer, but he did not realize as yet that this was because he was coming nearer to the lights of the great house and garden.  He only felt that the atmosphere was growing more intense, there was in the sadness more violence and secrecy -more -he hesitated for the word, and then said it with a jerk of laughter -Catastrophism.

More pines, more pathway slid past him, and then he stood rooted as by a blast of magic.  It is vain to say that he felt as if he had got into a dream; but this time he felt quite certain that he had got into a book.  For we human beings are used to inappropriate things; we are accustomed to the clatter of the incongruous; it is a tune to which we can go to sleep.  If one appropriate thing happens, it wakes us up like the pang of a perfect chord.  Something happened such as would have happened in such a place in a forgotten tale.

Over the black pine-wood came flying and flashing in the moon a naked sword -such a slender and sparkling rapier as may have fought many an unjust duel in that ancient park.  It fell on the pathway far in front of him and lay there glistening like a large needle.  He ran like a hare and bent to look at it.  Seen at close quarters it had rather a showy look:  the big red jewels in the hilt and guard were a little dubious.  But there were other red drops upon the blade which were not dubious.

He looked round wildly in the direction from which the dazzling missile had come, and saw that at this point the sable façade of fir and pine was interrupted by a smaller road at right angles; which, when he turned it, brought him in full view of the long, lighted house, with a lake and fountains in front of it.  Nevertheless, he did not look at this, having something more interesting to look at.

Above him, at the angle of the steep green bank of the terraced garden, was one of those small picturesque surprises common in the old landscape gardening; a kind of small round hill or dome of grass, like a giant mole-hill, ringed and crowned with three concentric fences of roses, and having a sundial in the highest point in the centre.  Kidd could see the finger of the dial stand up dark against the sky like the dorsal fin of a shark and the vain moonlight clinging to that idle clock.  But he saw something else clinging to it also, for one wild moment -the figure of a man.

Though he saw it there only for a moment, though it was outlandish and incredible in costume, being clad from neck to heel in tight crimson, with glints of gold, yet he knew in one flash of moonlight who it was.  That white face flung up to heaven, clean-shaven and so unnaturally young, like Byron with a Roman nose, those black curls already grizzled -he had seen the thousand public portraits of Sir Claude Champion.  The wild red figure reeled an instant against the sundial; the next it had rolled down the steep bank and lay at the American’s feet, faintly moving one arm.  A gaudy, unnatural gold ornament on the arm suddenly reminded Kidd of Romeo and Juliet; of course the tight crimson suit was part of the play.  But there was a long red stain down the bank from which the man had rolled -that was no part of the play.  He had been run through the body.

Mr Calhoun Kidd shouted and shouted again.  Once more he seemed to hear phantasmal footsteps, and started to find another figure already near him.  He knew the figure, and yet it terrified him.  The dissipated youth who had called himself Dalroy had a horribly quiet way with him; if Boulnois failed to keep appointments that had been made, Dalroy had a sinister air of keeping appointments that hadn’t.  The moonlight discoloured everything, against Dalroy’s red hair his wan face looked not so much white as pale green.

All this morbid impressionism must be Kidd’s excuse for having cried out, brutally and beyond all reason:  “Did you do this, you devil?”

James Dalroy smiled his unpleasing smile; but before he could speak, the fallen figure made another movement of the arm, waving vaguely towards the place where the sword fell; then came a moan, and then it managed to speak.

“Boulnois....  Boulnois, I say....  Boulnois did it... jealous of me...he was jealous, he was, he was...”

Kidd bent his head down to hear more, and just managed to catch the words: 

“Boulnois...with my own sword...he threw it...”

Again the failing hand waved towards the sword, and then fell rigid with a thud.  In Kidd rose from its depth all that acrid humour that is the strange salt of the seriousness of his race.

“See here,” he said sharply and with command, “you must fetch a doctor.  This man’s dead.”

“And a priest, too, I suppose,” said Dalroy in an undecipherable manner.  “All these Champions are papists.”

The American knelt down by the body, felt the heart, propped up the head and used some last efforts at restoration; but before the other journalist reappeared, followed by a doctor and a priest, he was already prepared to assert they were too late.

“Were you too late also?” asked the doctor, a solid prosperous-looking man, with conventional moustache and whiskers, but a lively eye, which darted over Kidd dubiously.

“In one sense,” drawled the representative of the Sun.  “I was too late to save the man, but I guess I was in time to hear something of importance.  I heard the dead man denounce his assassin.”

“And who was the assassin?” asked the doctor, drawing his eyebrows together.

“Boulnois,” said Calhoun Kidd, and whistled softly.

The doctor stared at him gloomily with a reddening brow -, but he did not contradict.  Then the priest, a shorter figure in the background, said mildly:  “I understood that Mr Boulnois was not coming to Pendragon Park this evening.”

“There again,” said the Yankee grimly, “I may be in a position to give the old country a fact or two.  Yes, sir, John Boulnois was going to stay in all this evening; he fixed up a real good appointment there with me.  But John Boulnois changed his mind; John Boulnois left his home abruptly and all alone, and came over to this darned Park an hour or so ago.  His butler told me so.  I think we hold what the all-wise police call a clue -have you sent for them?”

“Yes,” said the doctor, “but we haven’t alarmed anyone else yet.”

“Does Mrs Boulnois know?” asked James Dalroy, and again Kidd was conscious of an irrational desire to hit him on his curling mouth.

“I have not told her,” said the doctor gruffly -, “but here come the police.”

The little priest had stepped out into the main avenue, and now returned with the fallen sword, which looked ludicrously large and theatrical when attached to his dumpy figure, at once clerical and commonplace.  “Just before the police come,” he said apologetically, “has anyone got a light?”

The Yankee journalist took an electric torch from his pocket, and the priest held it close to the middle part of the blade, which he examined with blinking care.  Then, without glancing at the point or pommel, he handed the long weapon to the doctor.

“I fear I’m no use here,” he said, with a brief sigh.  “I’ll say good night to you, gentlemen.”  And he walked away up the dark avenue towards the house, his hands clasped behind him and his big head bent in cogitation.

The rest of the group made increased haste towards the lodge-gates, where an inspector and two constables could already be seen in consultation with the lodge-keeper.  But the little priest only walked slower and slower in the dim cloister of pine, and at last stopped dead, on the steps of the house.  It was his silent way of acknowledging an equally silent approach; for there came towards him a presence that might have satisfied even Calhoun Kidd’s demands for a lovely and aristocratic ghost.  It was a young woman in silvery satins of a Renascence design; she had golden hair in two long shining ropes, and a face so startingly pale between them that she might have been chryselephantine -made, that is, like some old Greek statues, out of ivory and gold.  But her eyes were very bright, and her voice, though low, was confident.

“Father Brown?” she said.

“Mrs Boulnois?” he replied gravely.  Then he looked at her and immediately said:  “I see you know about Sir Claude.”

“How do you know I know?” she asked steadily.

He did not answer the question, but asked another:  “Have you seen your husband?”

“My husband is at home,” she said.  “He has nothing to do with this.”

Again he did not answer; and the woman drew nearer to him, with a curiously intense expression on her face.

“Shall I tell you something more?” she said, with a rather fearful smile.  “I don’t think he did it, and you don’t either.”  Father Brown returned her gaze with a long, grave stare, and then nodded, yet more gravely.

“Father Brown,” said the lady, “I am going to tell you all I know, but I want you to do me a favour first.  Will you tell me why you haven’t jumped to the conclusion of poor John’s guilt, as all the rest have done?  Don’t mind what you say:  I -I know about the gossip and the appearances that are against me.”

Father Brown looked honestly embarrassed, and passed his hand across his forehead.  “Two very little things,” he said.  “At least, one’s very trivial and the other very vague.  But such as they are, they don’t fit in with Mr Boulnois being the murderer.”

He turned his blank, round face up to the stars and continued absentmindedly:  “To take the vague idea first.  I attach a good deal of importance to vague ideas.  All those things that ‘aren’t evidence’ are what convince me.  I think a moral impossibility the biggest of all impossibilities.  I know your husband only slightly, but I think this crime of his, as generally conceived, something very like a moral impossibility.  Please do not think I mean that Boulnois could not be so wicked.  Anybody can be wicked -as wicked as he chooses.  We can direct our moral wills; but we can’t generally change our instinctive tastes and ways of doing things.  Boulnois might commit a murder, but not this murder.  He would not snatch Romeo’s sword from its romantic scabbard; or slay his foe on the sundial as on a kind of altar; or leave his body among the roses, or fling the sword away among the pines.  If Boulnois killed anyone he’d do it quietly and heavily, as he’d do any other doubtful thing -take a tenth glass of port, or read a loose Greek poet.  No, the romantic setting is not like Boulnois.  It’s more like Champion.”

“Ah!” she said, and looked at him with eyes like diamonds.

“And the trivial thing was this,” said Brown.  “There were finger-prints on that sword; finger-prints can be detected quite a time after they are made if they’re on some polished surface like glass or steel.  These were on a polished surface.  They were half-way down the blade of the sword.  Whose prints they were I have no earthly clue; but why should anybody hold a sword half-way down?  It was a long sword, but length is an advantage in lunging at an enemy.  At least, at most enemies.  At all enemies except one.”

“Except one,” she repeated.

“There is only one enemy,” said Father Brown, “whom it is easier to kill with a dagger than a sword.”

“I know,” said the woman.  “Oneself.”

There was a long silence, and then the priest said quietly but abruptly:  “Am I right, then?  Did Sir Claude kill himself?”

“Yes” she said, with a face like marble.  “I saw him do it.”

“He died,” said Father Brown, “for love of you?”

An extraordinary expression flashed across her face, very different from pity, modesty, remorse, or anything her companion had expected:  her voice became suddenly strong and full.  “I don’t believe,” she said, “he ever cared about me a rap.  He hated my husband.”

“Why?” asked the other, and turned his round face from the sky to the lady.

“He hated my husband because...it is so strange I hardly know how to say it...because...”

“Yes?” said Brown patiently.

“Because my husband wouldn’t hate him.”

Father Brown only nodded, and seemed still to be listening; he differed from most detectives in fact and fiction in a small point -he never pretended not to understand when he understood perfectly well.

Mrs Boulnois drew near once more with the same contained glow of certainty.  “My husband,” she said, “is a great man.  Sir Claude Champion was not a great man:  he was a celebrated and successful man.  My husband has never been celebrated or successful; and it is the solemn truth that he has never dreamed of being so.  He no more expects to be famous for thinking than for smoking cigars.  On all that side he has a sort of splendid stupidity.  He has never grown up.  He still liked Champion exactly as he liked him at school; he admired him as he would admire a conjuring trick done at the dinner-table.  But he couldn’t be got to conceive the notion of envying Champion.  And Champion wanted to be envied.  He went mad and killed himself for that.”

“Yes,” said Father Brown; “I think I begin to understand.”

“Oh, don’t you see?” she cried; “the whole picture is made for that -the place is planned for it.  Champion put John in a little house at his very door, like a dependant -to make him feel a failure.  He never felt it.  He thinks no more about such things than -than an absent-minded lion.  Champion would burst in on John’s shabbiest hours or homeliest meals with some dazzling present or announcement or expedition that made it like the visit of Haroun Alraschid, and John would accept or refuse amiably with one eye off, so to speak, like one lazy schoolboy agreeing or disagreeing with another.  After five years of it John had not turned a hair; and Sir Claude Champion was a monomaniac.”

“And Haman began to tell them,” said Father Brown, “of all the things wherein the king had honoured him; and he said:  ’All these things profit me nothing while I see Mordecai the Jew sitting in the gate.’”

“The crisis came,” Mrs Boulnois continued, “when I persuaded John to let me take down some of his speculations and send them to a magazine.  They began to attract attention, especially in America, and one paper wanted to interview him.  When Champion (who was interviewed nearly every day) heard of this late little crumb of success falling to his unconscious rival, the last link snapped that held back his devilish hatred.  Then he began to lay that insane siege to my own love and honour which has been the talk of the shire.  You will ask me why I allowed such atrocious attentions.  I answer that I could not have declined them except by explaining to my husband, and there are some things the soul cannot do, as the body cannot fly.  Nobody could have explained to my husband.  Nobody could do it now.  If you said to him in so many words, ’Champion is stealing your wife,’ he would think the joke a little vulgar:  that it could be anything but a joke -that notion could find no crack in his great skull to get in by.  Well, John was to come and see us act this evening, but just as we were starting he said he wouldn’t; he had got an interesting book and a cigar.  I told this to Sir Claude, and it was his death-blow.  The monomaniac suddenly saw despair.  He stabbed himself, crying out like a devil that Boulnois was slaying him; he lies there in the garden dead of his own jealousy to produce jealousy, and John is sitting in the dining-room reading a book.”

There was another silence, and then the little priest said:  “There is only one weak point, Mrs Boulnois, in all your very vivid account.  Your husband is not sitting in the dining-room reading a book.  That American reporter told me he had been to your house, and your butler told him Mr Boulnois had gone to Pendragon Park after all.”

Her bright eyes widened to an almost electric glare; and yet it seemed rather bewilderment than confusion or fear.  “Why, what can you mean?” she cried.  “All the servants were out of the house, seeing the theatricals.  And we don’t keep a butler, thank goodness!”

Father Brown started and spun half round like an absurd teetotum.  “What, what?” he cried seeming galvanized into sudden life.  “Look here -I say -can I make your husband hear if I go to the house?”

“Oh, the servants will be back by now,” she said, wondering.

“Right, right!” rejoined the cleric energetically, and set off scuttling up the path towards the Park gates.  He turned once to say:  “Better get hold of that Yankee, or ‘Crime of John Boulnois’ will be all over the Republic in large letters.”

“You don’t understand,” said Mrs Boulnois.  “He wouldn’t mind.  I don’t think he imagines that America really is a place.”

When Father Brown reached the house with the beehive and the drowsy dog, a small and neat maid-servant showed him into the dining-room, where Boulnois sat reading by a shaded lamp, exactly as his wife described him.  A decanter of port and a wineglass were at his elbow; and the instant the priest entered he noted the long ash stand out unbroken on his cigar.

“He has been here for half an hour at least,” thought Father Brown.  In fact, he had the air of sitting where he had sat when his dinner was cleared away.

“Don’t get up, Mr Boulnois,” said the priest in his pleasant, prosaic way.  “I shan’t interrupt you a moment.  I fear I break in on some of your scientific studies.”

“No,” said Boulnois; “I was reading ‘The Bloody Thumb.’” He said it with neither frown nor smile, and his visitor was conscious of a certain deep and virile indifference in the man which his wife had called greatness.  He laid down a gory yellow “shocker” without even feeling its incongruity enough to comment on it humorously.  John Boulnois was a big, slow-moving man with a massive head, partly grey and partly bald, and blunt, burly features.  He was in shabby and very old-fashioned evening-dress, with a narrow triangular opening of shirt-front:  he had assumed it that evening in his original purpose of going to see his wife act Juliet.

“I won’t keep you long from ‘The Bloody Thumb’ or any other catastrophic affairs,” said Father Brown, smiling.  “I only came to ask you about the crime you committed this evening.”

Boulnois looked at him steadily, but a red bar began to show across his broad brow; and he seemed like one discovering embarrassment for the first time.

“I know it was a strange crime,” assented Brown in a low voice.  “Stranger than murder perhaps -to you.  The little sins are sometimes harder to confess than the big ones -but that’s why it’s so important to confess them.  Your crime is committed by every fashionable hostess six times a week:  and yet you find it sticks to your tongue like a nameless atrocity.”

“It makes one feel,” said the philosopher slowly, “such a damned fool.”

“I know,” assented the other, “but one often has to choose between feeling a damned fool and being one.”

“I can’t analyse myself well,” went on Boulnois; “but sitting in that chair with that story I was as happy as a schoolboy on a half-holiday.  It was security, eternity -I can’t convey it... the cigars were within reach...the matches were within reach... the Thumb had four more appearances to...it was not only a peace, but a plenitude.  Then that bell rang, and I thought for one long, mortal minute that I couldn’t get out of that chair -literally, physically, muscularly couldn’t.  Then I did it like a man lifting the world, because I knew all the servants were out.  I opened the front door, and there was a little man with his mouth open to speak and his notebook open to write in.  I remembered the Yankee interviewer I had forgotten.  His hair was parted in the middle, and I tell you that murder -”

“I understand,” said Father Brown.  “I’ve seen him.”

“I didn’t commit murder,” continued the Catastrophist mildly, “but only perjury.  I said I had gone across to Pendragon Park and shut the door in his face.  That is my crime, Father Brown, and I don’t know what penance you would inflict for it.”

“I shan’t inflict any penance,” said the clerical gentleman, collecting his heavy hat and umbrella with an air of some amusement; “quite the contrary.  I came here specially to let you off the little penance which would otherwise have followed your little offence.”

“And what,” asked Boulnois, smiling, “is the little penance I have so luckily been let off?”

“Being hanged,” said Father Brown.