Sir Humphrey Davy, after his first experiment with the inhalation of ether, exclaimed, "The Universe is composed solely of ideas."  Simon Iff had obtained that, and many another, experience, without the aid of drugs.  But although he was perfectly convinced that 'everything is illusion', like the most advanced transcendental philosophers, he was equally sure that all illusion was interwoven in a causal nexus.  There was no place in his universe for accident; there was no force so small that the cosmos failed to vibrate in due degree with it; and there was (further) no means of erasure applicable to any action.  Nothing could be destroyed; so it was there if you could only find it; and the task of finding it was nothing but the removal of the masks and veils.  He was only interested in crime because its detection sharpened the wits which he needed in the solution of philosophical problems.  He used to say that the fundamental laws of thought were the true obstacles to thinking.  "My conviction that two and two make four is the limitation that hinders me from realizing that they make five, as they must, or how could the universe itself have come from nothing?  It is the difference between the human mind and the Divine!"

That was the conclusion of a little interview that he gave to a particularly enterprising lady reporter.  He had succeeded for three months in keeping everybody away; but Miss Mollie Madison had been one too many for him.  She had found a way to induce his Japanese servant to let her wait in his apartment, and, once installed, had caught his interest by asking him point blank for his solution of the Pasquaney Puzzle.  "In me," she exclaimed dramatically, "you behold the unhappy Dolores Cass!"

"Excuse me, I do not," he answered; "I never heard of the Pasquaney Puzzle, and I know nothing of Dolores Cass.  But you are certainly not an unhappy anybody."

"Indeed, indeed, do not mock my misery!" she cried, tears standing in her big blue eyes.

"Delightful infant!  Old birds are not to be caught with chaff.  You're functioning - functioning in absolute harmony - which is the medical equivalent - in bad English - of being happy.  At this particular moment, I perceive, you are unusually happy, even for you; and as you are an American, I assume that you are, somehow or other, putting one over on me.  You're getting what you came for - be frank, now!  It won't hurt you with me!"

She dropped her masquerade and laughed at him like the beautiful doll she was.

"Surely, Mr. Iff!  I'm getting the most adorable interview."

"All right:  what can I do for you?"

"Do tell me your views on everything!"

This was walking into the enemy's country, had she known it.  Simple Simon took his revenge by doing as she asked.  When he got to the "two and two make five" peroration, she was sitting with note book and pencil fallen despairingly in her lap.

"It's a shame, truly it is, Mr. Iff!  You know I can't write up all that highbrow stuff.  It's absorbing to me, but the public won't stand for it."

"Oh Democracy!  Why is it that everybody I meet in this country is so eager to explain that everybody else is a fool?  If you really respected and trusted the people, you wouldn't treat them as mental and moral imbeciles.  I refer to your literature and your laws."

Miss Mollie Madison was not quite sure of the answer.

"Observe me, now!" said the mystic.  "I go on the opposite track.  The unknown fascinates me.  So I implore you humbly to put me wise to the dope on the Pasquaney Puzzle."

His sudden slang put her tremendously at her ease.  She took a packet of yellow paper from her vanity bag.  "I've got it all pat.  I've read nothing else for a week.  It was my one hope of getting you interested.  You can rely on the facts; most of this was written up by one of the best men in the office."

"We'll hope your bait of falsehood may catch a carp of truth.  Put in your clutch!"

"Lake Pasquaney lies among the mountains of New Hampshire.  It is about 17 miles in circumference.  Bristol, the nearest railway station, a town of 1200 inhabitants, is some three miles from the lower end.  The lake contains several islands, and its shores are dotted with summer villas, mostly of the long hut type, though here and there is a more pretentious structure, or a cluster of boarding-houses.  Bristol is about three hours from Boston, so the lake is a favourite summer resort, even for week-enders.  Automobile parties pass frequently, but keep mostly to the road on the east shore, that on the west being very rough.  The scenery is said by Europeans who know both to compare with Scotland or Switzerland without too serious disadvantage."

She looked merrily at him, and he smiled in grim appreciation of her subtle attack.

"Mrs. Cass is a woman of fifty-three years old, the widow of a wealthy Bostonian of good family, known all over the world for his attainments in pure mathematics."

"Oh, the Cass!  Indeed, this becomes very enthralling!  I was exceedingly intrigued by his monograph on hyperbolic geometry, and his criticism of Sir William Thomson's theory of a labile ether."

"Mrs. Cass has four children; Newton Gauss, thirty, a prominent engineer; Hope Ada, twenty-five; Dolores, twenty-two; and Emily, nineteen.  Last summer she rented a cottage which occupies one of the islands from July first to September thirtieth.  Hope Ada is married to a surgeon named Smith.  He and Newton used to come up from Boston whenever they could leave their work, and with them Geoffrey Travis, a shipowner, twenty-six years old, who was engaged to marry Dolores.  Emily was also engaged; but her fiancé, Arthur Green, was away in Los Angeles on some business connected with moving pictures.

"Mrs. Cass did a good deal of entertaining; every evening the cottage would be filled with a merry party of friends from other cottages on the lake.  The day was filled with boating, fishing, bathing, walking, motoring, every conceivable form of amusement.  There was not a disagreement or a dull moment, week after week.  The servants were all old and tried friends of the family."

The girl paused.  "Do you know, Mr. Iff, there is really no object in my telling you all these details?  The problem which arose on August the eighth is utterly insoluble.  It is entirely remote from the situation.  It means absolutely nothing."

"All the better.  But describe Dolores a little."

"She is a college girl, taking after her father in looks, and in mathematics.  She was a pupil, also, of Professor Hugo Munsterberg, and had made a profound study of the evidence for spirit return.  The year before, she had gone to Europe especially to sit with Eusapia Palladino and other famous mediums.  Her mind is always at work on these lines.  After a swim she would dry off on the beach with a note book.  But she is not a blue-stocking.  She is pretty, blonde, plump, lovely ....."

"You called her unhappy."

"I'm describing her as she was up to August the seventh."

"I see."

"She had not a care in the world.  She was the life of the whole family.  The others were more serious, but without her distinction.  She lived in extremes; one minute she would be romping like a mad creature, the next immersed in conic sections."

"Nobody envious?"

"Not a scrap.  Not enough imagination, I should say.  Besides, she was the most unselfish, sweet-tempered woman that God ever made."

"Enter August the eighth."

"With all the calm and brilliance of heaven itself!  On that morning, the three girls got up early for a swim.  They paddled up to a neighbouring islet in a canoe.  This islet contains a particularly secluded cove.  There is no cottage on it; only a few trees; there is no place to hide a rabbit.  It stands well out in the lake.  Dolores, though a brilliant athlete otherwise, was a poor swimmer; if she had been left alone on the islet she would have had to stay there till rescued.

"The three girls proceeded to bathe.  (Of course they had gone out in their bathing suits.)  Suddenly Hope missed Dolores, took alarm, and called her.  No answer.  She and Emily searched the islet; no sign of Dolores.  They became hysterical.  Just then they saw the other canoe; the men, Newton, Smith, and Travis, were paddling out to find them.  Hearing the girls scream, they redoubled their speed.  A further search was made; it was as futile as the former.  The whole party, except Smith, seem to have gone crazy with horror.  Smith had hard work to get them back to the cottage.  But, as they approached the island, what was their amazement to see Dolores walking up to the front door?  With shouts of relief and joy they paddled gaily onwards, not considering at that moment that an impossibility had occurred; that she literally couldn't have got there, and had therefore no sort of right to be there!

"They entered the cottage.  Mrs. Cass was at the breakfast table, Dolores was just sitting down, and saying 'What's the big idea, moms?'

"And then they all realized, as Mrs. Cass had just done, that it was not Dolores at all!

"Her lover and her sisters had run forward to embrace her; they recoiled in sudden terror.  Mrs. Cass was shocked almost senseless; yet it was she who first cried, 'Then where is Dolores?'

"Smith told his story; then Hope told hers.  Every one was aghast.

"Then Smith, whose scientific training seems to have served him well, grasped how bizarre the problem was.  He turned to the girl in the chair:  'Who are you, and how did you get here?'

"She stood up, pale as death.  'Is it a charade?' she cried.  'I'm Dolores; don't you know me?'

"'How did you get here?' insisted Smith.

"She could not or would not say.

"'That settles it,' said he, and went to the telephone to call up the police, and Maddingley, a detective inspector from Boston in whose powers he had great confidence.  Meanwhile a storm raged in the dining-room.

"'Don't I know my own daughter?' cried Mrs. Cass.

"'Where is the ring I gave you, if you are Dolores?' said her lover.

"The argument raged all morning.  Smith rang up a general alarm; the whole lakeside population turned out to scour the woods, to dredge the lake about the fatal islet.  Nothing was found.  Maddingley had caught the early train from Boston and arrived a little before noon.  He entered what he thought was an insane asylum!  He and Smith obtained silence, and a rational examination began.  There was absolute agreement between all the witnesses.  The stranger looked like Dolores, talked like her, acted like her; there wasn't a thing missing of the tangible kind, except the ring; but it was not Dolores.  She, on her side, underwent the most critical tests.  She knew the family history, every detail correct; she described the position of the furniture in her bedroom, the contents of every drawer, even the secrets of a cashbox with a Yale lock, which she asked them to open, after telling them where she had hidden the key.  The servants were examined also; they agreed with the family.  It was the story of the Tichborne Claimant reversed.  The only flaws in her case were her failure to explain her arrival from the islet, and the absence of her engagement ring; the only flaw in theirs was the appalling question 'Then where is Dolores?'

"Maddingley was of course at a complete standstill.  He could only form one conclusion, that the whole family, including the girl, had entered into a conspiracy to lie.  He washed his hands of the matter, and returned to Boston, where he angrily and rather foolishly opened his mind to the Press.

"Unfortunately, most of the friends of Dolores in Boston were entirely on the side of the family.  Everyone admitted the astonishing physical resemblance; every one admitted the force of the fact that she knew every conceivable thing that Dolores had known; every one agreed that the disappearance of one girl to nowhere, concident with the arrival of an exactly similar girl from nowhere, was an unparalleled and incredible improbability.  But they clung to their 'interior certainty' based on unavowable, impalpable, unconscious impression - for all the world like so many mystics!  Mrs. Cass turned the imposter out of the cottage, after fitting her with an old dress; for the stranger was unquestionably wearing Dolores' bathing suit.  And then she put up the shutters of the cottage, and went back to Boston.  The family went into mourning, and refused to see any but the most intimate friends for the rest of the summer.

"The stranger found asylum with the proprietor of a sensational newspaper, who saw his way to exploit her.  He had her psychoanalyzed, and tested in fifty different ways; her handwriting was photographed and enlarged - I may say that her bank cashed her first check without a word, and then went back on itself, refused to pay any more, but on the other hand refused to prosecute for forgery.  She sued them; they put up a half-hearted fight, and she won handsomely.  They hunted through the effects of the missing girl for fingerprints ... there was no end to it.

"Jenkins, of the 'Turkey-Buzzard', most certainly knew his business.  He got experts from all over the country at loggerheads; he kept the whole of the United States in a turmoil for six months on end.  It's still going on, fairly strong; safe for an argument in any gathering in the United States.  The stranger's doing well, too; they say she stuck out for a thousand a week.  And she's certainly earned it!  That looks, by the way, as if she were not Dolores; for Dolores had all the money she needed.  And Dolores wouldn't have given her family all that sorrow.  No, if it's she, she must have one whale of a motive!"

"And what do you think?"

"I can't.  I can't see what happened to the Dolores of the islet, unless they're all lying.  And people don't turn out the best beloved for a joke; not people like the Cass family."

"Have you photographs?"

Miss Molly Madison promptly produced a docket.

"Nothing to go by, as I expected," grunted Simon Iff.  "Yet - this is last week's - was it taken last week?"

"Surely.  New dress; new pose.  The Press has to keep up to date in this country!"

"Well, I suppose the best of us has a failing.  This girl doesn't seem to be suffering as much as one would expect.  She's got the anguished look, all right; but she hasn't lost much flesh since the fatal eighth of August."

"Oh, some people get fat on worry."

"Then you think it is Dolores, after all?"

Miss Mollie Madison was caught.  She gave up.  "Yes, I do; I think everybody does; only that makes the mystery more insoluble than ever."

"Then you think psychological difficulties are more serious than physical ones?"

"How you do pick one up!  Yes, I suppose that's what I do think."

"My own course is simple.  I will publish my solution.  Or - wait - that's hardly fair.  Was Dolores in love with Travis?'

"Very much.  Friends and playmates from childhood; not another man in her life.  We went through that with a toothcomb."

"Mr. Geoffrey Travis is not so faithful.  He is engaged to be married to another girl."

"Impossible!  He's heartbroken!"

"Ah, it's the double standard, I'm afraid!"

"I won't believe it of Geoffrey Travis."

"Well, you watch the papers.  If there isn't an announcement to that effect in three days, you may come up here and get the box of gloves I'm betting you about it."

"Is it a joke?"

"Well, it is rather.  Don't put it in your interview, though, or you'll spoil everything.  But you may say that - er - I think I'll write it down for you; I want verbal accuracy in this one thing please.  'Mr. Iff said that the case showed clear evidence of certain influences connected with what is commonly and erroneously called the supernatural; and that he would publish a full analysis of the case in these columns, and in the Journals devoted to Psychical Research, in one month from date.'  I think that will do.  Only - don't put it in unless I'm wrong about Travis.  So come up at four o'clock on Friday, and have tea, and we'll have another chat."

"You're as mysterious as the case itself."

"Just so," smiled Simon.  "Quite plain sailing, if you think it out!"

Miss Mollie Madison sailed queenly out of the apartment, blessed above women in the possession of a number one 'scoop.'

Simon Iff called to his Jap to pack a bag.  "I'll be back Thursday evening, at the latest," said he.

And on Thursday morning, Miss Mollie Madison, waking late after a hard night covering somebody's début, opened her paper at the Society Column to read the formal announcement of the engagement of Mr. Geoffrey Travis to Miss Alberta Crosman of Philadelphia.

"How could he possibly know?" she wailed.  "He is a magician; it is all supernatural!  But oh! what a scoop! what a scoop!"

She made the world's record for a lady's toilet look like a basket of eggs dropped from the Woolworth Building, and reached the office to write up the prophecy just about the time when Simon Iff, sitting with Geoffrey Travis in his office in Boston, saw the door flung open and an impetuous young lady, with a really remarkable diamond on her business finger, burst in with the cry "Don't you dare, Geoffrey, don't you dare!"

By the men's faces she saw that she had been tricked; but she didn't mind much.  Simon Iff slipped out, with a wave of the finger-tips.  "Won't disturb you now; see you at the wedding."

"Don't forget you're the best man!" shouted Geoffrey, through the waves of loosened gold that flowed about his head.

It was with reverence and godly fear that Miss Mollie Madison knocked at the door of 'that uncanny old man' on Thursday afternoon.  She had just heard on long distance of the reappearance of the real Dolores, and Simon Iff's reference to the supernatural, which she had of course completely misunderstood, had set her imagination awhirl.

She was decidedly reassured to find him making the tea in a very fantastic and elaborate, but very practical manner, with one hand, and toasting muffins over a silver spirit lamp with the other.

"Welcome, my child!" he cried.  "It may be you can lift the burden from my soul!"

She offered her utmost:  what was the trouble?

"I despair of humanity," cried he.  "I can trust no living creature either to make tea or to toast muffins, save myself.  Yet they must be accomplished simultaneously, or all is lost!"  He comically resigned the task to her.  "You finish it!  I must lament alone.  I am getting old.  The appalling castastrophe in the Pasquaney Puzzle has ruined my last hope for Man!"

"Why, haven't you heard?" she said, aglow.  "The real Dolores has come back this morning."

"I was there," said Simon.  "Pour out the tea, and I will declare to you this mystery.  But I will declare it decently and in order:  the castastrophe whereof I speak will therefore come last."

"I love being teased."

"It was evident from the first that the family was not lying.  A joke might have been well enough for a day or a week, though a highbred Baastan clan is the last place on earth - if Baaston can be said to be on earth - to look for it.  It is unthinkable that they should keep it up for six months and more.  One might have explained the mere disappearance of Dolores by supposing that the two girls were lying for some strong motive, but that would involve a Second Girl, with all the difficulties attached to that theory.  It was pretty clear to me that the Casses were absolutely honest, and absolutely bewildered.

"It followed that Dolores herself was the mainspring of the mechanism.  She could not have been drowned in the shallow water of a calm lake within a few yards of her sisters; she could not have been kidnapped.  No; she was the creator of the plot.

"Now then, we have to find a motive for her action.  Here is a high-minded and noble girl, without a care in the world, loved and loving.  We must exclude any idea of scandal or even of escapade.  She was a jolly happy girl.  But she had more in her than that; and that was not any secret passion or vice.  It was an intense ambition to follow her father to an equal fame.  She put in every spare moment on the higher mathematics or on the problems of psychical research.

"I said to myself that a very strong motive must be attached to this - er - I believe the Baaston for it is Urge.

"And then I saw instantly a quite inexplicable coincidence.  You told me of her 'profound study of spirit return'.  The crux of that problem is proof of identity.  And the Pasquaney Puzzle is just such a problem.  It was impossible to doubt that Dolores had deliberately invented a test case, and challenged all the wise men of the world to solve it.  She knew well enough that the notoriety would attract every intelligence on the planet, if she only gave them time enough.  It would not do to give the game away in a week or a month.

"No scandal would be attached to the family, once her motive was made clear by the publication of a thesis analysing the evidence in the case.

"Her action would cause extreme pain to those she loved; but science first!  She would atone by the distinction of her achievement.  At twenty-two one has such ideas.

"So far, so good; but how did such an idea arise in her mind?  Possibly long ago, as an A. B. case; but if so, she must have seen immediately that it was perfectly impracticable.  In what conceivable set of circumstances could she get her mother and sisters and brother and lover and friends to disown her?  By some change of manner?  Some assumed forgetfulness of her identity?  They would merely have supposed her ill or insane; no public controversy could ever have arisen.  No:  the only plan would be to have a Second Girl; and my idea is that she found the Second Girl first, and that the likeness put the scheme into her head.

"Just then a flash of memory came to assist me.  I met Professor Cass several times in Europe.  He was just such a man as I imagine Dolores to be a woman.  He would go to any lengths in the interest of his work.  He once nearly killed himself in an experiment with digitalis and hyoscine - he wanted to map out the conflicting curves in the record of his heart action produced by those drugs.  And as for some reason or other he couldn't bring Mrs. Cass on his travels, and as he 'couldn't work without her inspiration', he simply contracted a liaison with a woman as much like her as possible!  It occurred to me that some such union had been fruitful, and that Dolores, by accident or design, had met a half-sister on the trip to Europe, two years ago, of which you told me.

"Now suppose that this half-sister, or some other girl equally well qualified, agrees to the suggestion of Dolores.  They must first put in a great deal of work, prompting the Second Girl in family knowledge, teaching her to imitate Dolores' handwriting, and so on; and they must then invent a dramatic quick change scene, if possible one so extraordinary as to exclude all trickery - except The Trick.  Dolores had made a special study of this with her 'mediums'.  She thought of the summer cottage, and an excellent idea came to her.  She would learn to swim like a fish, and keep up the pretence of being a duffer.  I suspected something of that sort from the first minute - the statement of her incompetence was as weak as negatives usually are - especially in spiritualistic circles.  When a man begins to argue that a medium couldn't know this or couldn't do that, he's either an expert or an ignoramus; and he's rarely an expert.

"She would need one further essential, and co-operation of somebody powerful, somebody who could hide the Second Girl until the right moment, and arrange for her own getaway and concealment while the play was playing.  Probably she knew already of some people of wealth, deeply interested in the spirit problem, who would join the merry throng.

"I could not see any other solution that was not barred either by the psychology or by the physics of the known facts."

Miss Mollie Madison had got it all down in her note book.  As Simon Iff was now politely offering her a cigarette, she decided to ask what she wanted to know.  Analysis and deduction were nothing in her young life; but how did 'that uncanny old man' prophesy the engagement of Geoffry Travis, whose name he had just heard for the first time?

"I'm a vain old person, my dear; I ought to have let well alone.  But I'm still young enough to be annoyed that a chit of a girl should think to puzzle me, even if she merely includes me in Carlyle's 'mostly fools'.  So I determined to twist my knuckles in the golden locks of Miss Dolores and drag her to my wigwam.  Therefore I arranged with you - as a last resort - to publish that I would deal with the matter from the point of view of Psychical Research.  She would see the point at once, of course.  Her Press-Cutting people must be keeping her supplied with all possible material for her book.  She would know my name, I hoped, and know from that notice that I knew the whole story, and meant to take the wind out of her sails by publishing my own analysis of the identity problem before she had got hers ready.  In which case, good-bye to her fame, to the whole purpose of her plot.

"But alas for humanity!  I bethought me also of a simple plan, a plan which would humiliate her even more before me.  I would tell Travis my conclusions, and end:  'If you want her back, you've only got to advertise that you've got a new girl now.'  So, as I said before - and Shakespeare even earlier! - that bait of falsehood took that carp of truth.  She came round in a rage the next morning, and delivered the goods.  To think that one whose aspiration soared so high should fall so low!  'Tis vaulting ambition which o'erleaps itself, and falls on the other!  To aim at mathematics and to hit mere man!"

"Oh how wonderful you are, Mr. Iff!  How you know the Heart of a Pure Woman!"

"Oh no, my dear, it's not original at all; it's just a modern adaptation of Solomon and the Baby.  And now I have to run away and dress for dinner; you may publish all I've said, except the bit about the half-sister.  Just invent a marvellous coincidence, won't you?  It's the crucial difficulty of the whole business, but nobody will know that.  So run away, little girl, run away and play with your nice toy, the Public!"