"Your opinion is of course conclusive," Arthur answered with unfeigned humility, his eyes almost bursting with the tears he would not let come to the surface. "It will be a great disappointment to my friend, but I have no doubt he will accept your verdict."

"Not a bit of it, my dear sir," the professor put in quickly. "Not a bit of it. These crazy fellows always stick to their own opinions, and think you a perfect fool for disagreeing with them. Mark my words, Mr. Greatrex, your friend will still go on believing, in spite of everything, that his roundabout reasoning upon that preposterous square-root-of-Pi theorem is sound mathematics."

And Arthur, looking within, felt with a glow of horror that the theorem in question seemed to him at that moment more obviously true and certain in all its deductions than it had ever done before since the first day that he conceived it. How very mad he must be after all.

He thanked Professor Linklight as well as he was able for his kindness in looking over the paper, and groped his way blindly through the passage to the front door and out into the square. Thence he staggered home wearily, convinced that it was all over between him and Hetty, and that he must make up his mind forthwith to his horrible destiny.

If he had only known at that moment that forty years earlier Professor Linklight had used almost the same words about Young's theory of undulations, and had since used them about every new discovery from that day to the one on which he then saw him, he might have attached less importance than he actually did to this supposed final proof of his own insanity.

As Arthur entered his lodgings he hung his hat up on the stand in the passage. There was a little strip of mirror in the middle of the stand, and glancing at it casually he saw once more that awful face – his own – distorted and almost diabolical, which he had learnt so soon to hate instinctively as if it were a felon's and a murderer's. He rushed away wildly into his little sitting-room, and flung his manuscript on the table, almost without observing that his friend Freeling, the rising physiologist, was quietly seated on the sofa opposite.

"What's this, Arthur?" Freeling asked, taking it up carelessly and glancing at the title. "You don't mean to say that you've finally written out that splendid idea of yours about the interrelations of energy?"

"Yes, I have, Harry: I have, and I wish to heaven I hadn't, for it's all mad and silly and foolish and meaningless!"

"If it is, then I'm mad too, my dear fellow, for I think it's the most convincing thing in physics I ever listened to. Let me have the manuscript to look over, and see how you've worked out those beautiful calculations about the square root of Pi, will you?"

"Take the thing, for heaven's sake, and leave me, Harry, for if I'm not left alone I shall break down and cry before you." And as he spoke he buried his head in his arm and sobbed like a woman.

Dr. Freeling knew Arthur was in love, and was aware that people sometimes act very unaccountably under such circumstances; so he did the wisest thing to be done then and there: he grasped his friend's arm gently with his hand, spoke never a word, and, taking up his hat and the manuscript, walked quietly out into the passage. Then he told the landlady to make Mr. Greatrex a strong cup of tea, with a dash of brandy in it, and turned away, leaving Arthur to solitude and his own reflections.

That evening's post brought Arthur Greatrex two letters, which finally completed his utter prostration. The first he opened was from Dr. Abury. He broke the envelope with a terrible misgiving, and read the letter through with a deepening and sickening feeling of horror. It was not he alone, then, who had distorted the secret of his own incipient insanity. Dr. Abury's practised eye had also detected the rising symptoms. The doctor wrote kindly and with evident grief; but there was no mistaking the firm purport of his intentions. Conferring this morning with his professional friend Warminster, a case had been mentioned to him, without a name, which he at once recognized as Arthur's. He recalled certain symptoms he had himself observed, and his suspicions were thus vividly aroused. Happening accidentally to follow Arthur in the street he was convinced that his surmise was correct, and he thought it his duty both to inform Arthur of the danger that encompassed him, and to assure him that, deeply as it grieved him to withdraw the consent he had so gladly given, he could not allow his only daughter to marry a man bearing on his face the evident marks of an insane tendency. The letter contained much more of regret and condolence; but that was the pith that Arthur Greatrex picked out of it all through the blinding tears, that dimmed his vision.

The second letter was from Hetty. Half guessing its contents, he had left it purposely till the last, and he tore it open now with a fearful sinking feeling in his bosom. It was indeed a heart-broken, heart-breaking letter. What could be the secret which papa would not tell her? Why had not Arthur come yesterday? Why could she never marry him? Why was papa so cruel as not to tell her the reason? He couldn't have done anything in the slightest degree dishonourable, far less anything wicked: of that she felt sure; but, if not, what could be this horrible, mysterious, unknown barrier that was so suddenly raised between them? "Do write, dearest Arthur, and relieve me from this terrible, incomprehensible suspense; do let me know what has happened to make papa so determined against you. I could bear to lose you – at least I could bear it as other women have done – but I can't bear this awful uncertainty, this awful doubt as to your love or your constancy. For heaven's sake, darling, send me a note somehow! send me a line to tell me you love me. Your heart-broken

"Hetty."

Arthur took his hat, and, unable to endure this agony, set out at once for the Aburys'. When he reached the door, the servant who answered his ring at the bell told him he could not see the doctor; he was engaged with two other doctors in a consultation about Miss Hetty. What was the matter with Miss Hetty, then? What, didn't he know that? Oh, Miss Hetty had had a fit, and Dr. Freeling and Dr. MacKinlay had been called in to see her. Arthur did not wait for a moment, but walked upstairs unannounced, and into the consulting room.

Was it a very serious matter? Yes, Freeling answered, very serious. It seemed Miss Abury had had a great shock – a great shock to her affections – which, he added in a lower voice, "you yourself can perhaps best explain to me. She will certainly have a long illness. Perhaps she may never recover."

"Come out into the conservatory, Harry," said Arthur to his friend. "I can tell you there what it is all about."

In a few words Arthur told him the nature of the shock, but without describing the particular symptoms on which the opinion of his supposed approaching insanity was based. Freeling listened with an incredulous smile, and at the end he said to his friend gently, "My dear Arthur, I wish you had told me all this before. If you had done so, we might have saved Miss Abury a shock which may perhaps be fatal. You are no more going mad than I am; on the contrary, you're about the sanest and most clear-headed fellow of my acquaintance. But these mad-doctors are always finding madness everywhere. If you had come to me and told me the symptoms that troubled you, I should soon have set you right again in your own opinion. To have gone to Warminster was most unfortunate, but it can't be helped now. What we have to do at present is to take care of Miss Abury."

Arthur shook his head sadly. "Ah," he said, "you don't know the real gravity of the symptoms I am suffering from. I shall tell you all about them some other time. However, as you say, what we have to think about now is Hetty. Can you let me see her? I am sure if I could see her it would reassure her and do her good."

Dr. Abury was at first very unwilling to let Arthur visit Hetty, who was now lying unconscious on the sofa in her own boudoir; but Freeling's opinion that it might possibly do her good at last prevailed with him, and he gave his permission grudgingly.

Arthur went into the room silently and took his seat beside the low couch where the motherless girl was lying. Her face was very white, and her hands pale and bloodless. He took one hand in his: the pulse was hardly perceptible. He laid it down upon her breast, and leaned back to watch for any sign of returning life in her pallid cheek and closed eyelids.

For hours and hours he sat there watching, and no sign came. Dr. Abury sat at the bottom of the couch, watching with him; and as they watched, Arthur felt from time to time that his face was again twitching horribly. However, he had only thoughts for one thing now: would Hetty die or would she recover? The servants brought them a little cake and wine. They sat and drank in silence, looking at one another, but each absorbed in his own thoughts, and speaking never a word for good or evil.

At last Hetty's eyes opened. Arthur noticed the change first, and took her hand in his gently. Her staring gaze fell upon him for a moment, and she asked feebly, "Arthur, Arthur, do you still love me?"

"Love you, Hetty? With all my heart and soul, as I have always loved you!"

She smiled, and said nothing. Dr. Abury gave her a little wine in a teaspoon, and she drank it quietly. Then she shut her eyes again, but this time she was sleeping.

All night Arthur watched still by the bedside where they put her a little later, and Dr. Abury and a nurse watched with him. In the morning she woke slightly better, and when she saw Arthur still there, she smiled again, and said that if he was with her, she was happy. When Freeling came to inquire after the patient, he found her so much stronger, and Arthur so worn with fear and sleeplessness, that he insisted upon carrying off his friend in his brougham to his own house, and giving him a slight restorative. He might come back at once, he said; but only after he had had a dose of mixture, a glass of brandy and seltzer, and at least a mouthful of something for breakfast.

As Freeling was drawing the cork of the seltzer, Arthur's eye happened to light on a monkey, which was chained to a post in the little area plot outside the consulting-room. Arthur was accustomed to see monkeys there, for Freeling often had invalids from the Zoo to observe side by side with human patients; but this particular monkey fascinated him even in his present shattered state of nerves, because there was a something in its face which seemed strangely and horribly familiar to him. As he looked, he recognized with a feeling of unspeakable aversion what it was of which the monkey reminded him. It was making a series of hideous and apparently mocking grimaces – the very self-same grimaces which he had seen on his own features in the mirror during the last day or two! Horrible idea! He was descending to the level of the very monkeys!

The more he watched, the more absolutely identical the two sets of grimaces appeared to him to be. Could it be fancy or was it reality? Or might it be one more delusion, showing that his brain was now giving way entirely? He rubbed his eyes, steadied his attention, and looked again with the deepest interest. No, he could not be mistaken. The monkey was acting in every respect precisely as he himself had acted.

"Harry," he said, in a low and frightened tone, "look at this monkey. Is he mad? Tell me."

"My dear Arthur," replied his friend, with just a shade of expostulation in his voice, "you have really got madness on the brain at present. No, he isn't mad at all. He's as sane as you are, and that's saying a good deal, I can assure you."

"But, Harry, you can't have seen what he's doing. He's grimacing and contorting himself in the most extraordinary fashion."

"Well, monkeys often do grimace, don't they?" Harry Freeling answered coolly. "Take this brandy and you'll soon feel better."

"But they don't grimace like this one," Arthur persisted.

"No, not like this one, certainly. That's why I've got him here. I'm going to operate upon him for it under chloroform, and cure him immediately."

Arthur leaped from his seat like one demented. "Operate upon him, cure him!" he cried hastily. "What on earth do you mean, Harry?"

"My dear boy, don't be so excited," said Freeling. "This suspense and sleeplessness have been too much for you. This is antivivisection carried ad absurdum. You don't mean to say you object to operations upon a monkey for his own benefit, do you? If I don't cut a nerve, tetanus will finally set in, and he'll die of it in great agony. Drink off your brandy, and you'll feel better after it."

"But, Harry, what's the matter with the monkey? For heaven's sake, tell me!"

Harry Freeling looked at his friend for the first time a little suspiciously. Could Warminster be right after all, and could Arthur really be going mad? It was so ridiculous of him to get into such a state of flurry about the ailments of a tame monkey, and at such a moment, too! "Well," he answered slowly, "the monkey has got facial distortions due to a slight local paralysis of the inhibitory nerves supplied to the buccal and pharyngeal muscles, with a tendency to end in tetanus. If I cut a small ganglion behind the ear, and exhibit santonin, the muscles will be relaxed; and though they won't act so freely as before, they won't jerk and grimace any longer."

"Does it ever occur in human beings?" Arthur asked eagerly.

"Occur in human beings? Bless my soul, yes! I've seen dozens of cases. Why, goodness gracious, Arthur, it's positively occurring in your own face at this very moment!"

"I know it is," Arthur answered in an agony of suspense. "Do you think this twitching of mine is due to a local paralysis of the inhibitories, such as you speak of?"

"Excuse my laughing, my dear fellow; you really do look so absurdly comical. No, I don't think anything about it. I know it is."

"Then you believe Warminster was wrong in taking it for a symptom of incipient insanity?"

It was Freeling's turn now to jump up in surprise. "You don't mean to tell me, Arthur, that that was the sole ground on which that old fool, Warminster, thought you were going crazy?"

"He didn't see it himself," answered Arthur, with a sigh of unspeakable relief. "I only described it to him, and he drew his inference from what I told him. But the real question is this, Harry: Do you feel quite sure that there's nothing more than that the matter with me?"

"Absolutely certain, my dear fellow. I can cure you in half an hour. I've done it dozens of times before, and know the thing as well as you know an ordinary case of scarlet fever."

Arthur sighed again. "And perhaps," he said bitterly, "this terrible mistake may cost dear Hetty her life!"

He drank off the brandy, ate a few mouthfuls of food as best he might, and hastened back to the Aburys'. When he got there he learned from the servant that Hetty was at least no worse; and with that negative comfort he had for the moment to content himself.

Hetty's illness was long and serious; but before it was over Freeling was able to convince Dr. Abury of his own and his colleague's error, and to prove by a simple piece of surgery that Arthur's hideous grimaces were due to nothing worse than a purely physical impediment. The operation was quite a successful one; but though Greatrex's face has never since been liable to these curious contortions, the consequent relaxation of the muscles has given his features that peculiarly calm and almost impassive expression which everybody must have noticed upon them at the present day, even in moments of the greatest animation. The difficulty was how to break the cause of the temporary mistake to Hetty, and this they were unable to do until she was to a great extent convalescent. When once the needful explanation was over, and Arthur was able once more to kiss her with perfect freedom from any tinge of suspicion on her part, he felt that his paradise was at last attained.

A few days before the deferred date fixed for their wedding, Freeling came into the doctor's drawing-room, where Hetty and Arthur were sitting together, and threw a letter with a French official stamp on its face down upon the table. "There," he said, "I find all the members of the Académie des Sciences at Paris are madmen also!"

Hetty smiled faintly, and said with a little earnestness in her tone, "Ah, Dr. Freeling, that subject has been far too serious a one for both of us to make it pleasant jesting."

"Oh, but look here, Miss Abury," said Freeling; "I have to apologise to Arthur for a great liberty I have ventured to take, and I think it best to begin by explaining to you wherein it consisted. The fact is, before you were ill, Arthur had just written a paper on the interrelations of energy, which he showed to that pompous old nincompoop, Professor Linklight. Well, Linklight being one of those men who can never see an inch beyond his own nose, had the incomprehensible stupidity to tell him there was nothing in it. Thereupon your future husband, who is a modest and self-depreciating sort of fellow, was minded to throw it incontinently into the waste-paper basket. But a friend of his, Harry Freeling, who flatters himself that he can see an inch or two beyond his own nose, read it over, and recognized that it was a brilliant discovery. So what does he go and do – here comes in the apologetic matter – but get this memoir quietly translated into French, affix a motto to it, put it in an envelope, and send it in for the gold medal competition of the Académie. Strange to say, the members of the Académie turned out to be every bit as mad as the author and his friend; for I have just received this letter, addressed to Arthur at my house (which I have taken the further liberty of opening), and it informs me that the Académie decrees its gold medal for physical discovery to M. Arthur Greatrex, of London, which is a subject of congratulation for us three, and a regular slap in the face for pompous old Linklight."

Hetty seized Freeling's two hands in hers. "You have been our good genius, Dr. Freeling," she said with brimming eyes. "I owe Arthur to you; and Arthur owes me to you; and now we both owe you this. What can we ever do to thank you sufficiently?"

Since those days Hetty and Arthur have long been married, and Dr. Greatrex's famous work (in its enlarged form) has been translated into all the civilized languages of the world, as well as into German; but to this moment, happy as they both are, you can read in their faces the lasting marks of that one terrible anxiety. To many of their friends it seemed afterwards a mere laughing matter; but to those two, who went through it, and especially to Arthur Greatrex, it is a memory too painful to be looked back upon even now without a thrill of terrible recollection.