Émilie Varenne received the letter on a Thursday, although she subsequently found it difficult to establish which Thursday it had been.
The envelope was of heavy cream paper, addressed in a hand that she recognised without being able to place. It bore neither stamp nor postmark. Her name was written correctly, including the accent, and beneath it the address of the apartment in which she had lived until the previous March.
Inside was a single sheet.
Madame,
We understand that you have recently completed your work concerning the persistence of identity under non-sequential observation.
There are certain consequences of your result which we believe you would find interesting.
Should you wish to visit us, a room has been prepared.
You are under no obligation.
There was no signature.
At the bottom of the page appeared a mathematical expression.
Émilie read it once, then again, and placed the letter carefully upon her desk.
The expression was hers. She had derived it eleven days earlier, after several months of unsuccessful attempts to reconcile two incompatible descriptions of an observer's temporal continuity. She had shown it to nobody. Indeed, she had not yet decided whether it was correct.
What disturbed her was not its appearance in the letter, but the slight alteration made to its final term.
She had written an equality.
The letter contained an equivalence.
It was the correction she had been unable to justify.
For a considerable time she remained seated, regarding the paper with an attention that was not quite fear. Her first impulse was to telephone the department. Her second was to examine the locks on the apartment door. She did neither.
Instead she took out her notebook and began to calculate.
By midnight she had established that the correction was valid, although its validity depended upon a proposition she had never seriously entertained: that personal identity need not be preserved under the ordering of events.
At half past one she made coffee.
At two she wrote a reply accepting the invitation.
Only when she had sealed the envelope did she notice that the letter contained no address to which her reply might be sent.
She left it upon the desk.
In the morning it was gone.
In its place lay a small card bearing the words:
Thursday. Four o'clock. You will be expected.
Beneath them, in handwriting that was unmistakably her own, someone had added:
You have already been.
Émilie was forty-three years old. She had never married, although she had lived for seven years with a man whose departure had occasioned less grief than she had expected and considerably more administrative inconvenience. She occupied an apartment on the fourth floor of a respectable building in the sixth arrondissement, kept few possessions, and maintained a professional reputation for a certain severity of thought that her colleagues sometimes mistook for severity of temperament.
She was not severe. She simply disliked imprecision.
Her students found her courteous, exacting and occasionally difficult to please. She corrected errors without embarrassment and accepted corrections to her own work without resentment. She did not regard intellectual honesty as a virtue requiring celebration. It was merely the minimum condition under which an argument deserved attention.
She had been raised without religion. Her father, a civil engineer, regarded metaphysical speculation as an unfortunate consequence of insufficient employment. Her mother had been a pianist whose interest in religious music extended no further than its harmonic structure. Émilie had inherited something of both attitudes, although she was more tolerant of metaphysics than her father and less susceptible to beauty than her mother.
She had never experienced what religious people called revelation.
She distrusted the word, not because she considered revelation impossible, but because it appeared to describe an interpretation of an experience rather than an independently established source of information.
A person might encounter something extraordinary. That did not establish who, or what, had arranged the encounter.
This distinction had always seemed elementary.
It would become important.
On Friday morning she examined the card.
The handwriting was certainly hers. There was a slight backward inclination to the capital T, and the final stroke of the word been terminated in the small upward movement she had acquired during
childhood and never quite corrected. She compared it with several pages of her notebooks.
She could discover no discrepancy.
She photographed both sides of the card, placed it in an envelope, and telephoned the building's concierge.
Madame Fournier assured her that nobody had entered the apartment during the night. She was quite certain of this, since the lift had been out of service since eleven and she had heard no one on the stairs.
Émilie thanked her.
She did not mention that she herself had used the lift shortly after midnight.
Such discrepancies, she knew, were usually resolved by the discovery that someone had mistaken a time, a date or an event. Human memory was not a recording apparatus. It was a reconstruction, and frequently an unreliable one.
She checked her telephone. It showed that she had returned home at 19:16 on Thursday evening. Her location history agreed. The café where she had bought coffee had charged her account at 19:08.
She had no evidence that she had entered the building after midnight, beyond the memory of having done so.
She wrote down both accounts without attempting to reconcile them.
At eleven she went to the university.
Her office was on the second floor of a building whose architectural character suggested that the administration had once commissioned a prison and subsequently changed its mind. There were books on the shelves, papers arranged in three orderly stacks, and a photograph of her parents taken shortly before her mother's death.
On the desk lay a folder she did not recognise.
It was grey, unmarked, and contained a single page.
At the top was the title of her unfinished paper.
Beneath it appeared a date six weeks in the future.
The page contained no text. There was only a signature at the bottom.
Her own.
Émilie sat down.
She examined the paper for some minutes, then opened the folder to make certain that nothing had been concealed between its covers.
She considered the possibility of an elaborate practical joke. It was not impossible. Several of her colleagues possessed the necessary access to her office, and one or two had sufficiently childish temperaments to find the exercise amusing.
The alteration to her equation, however, remained unexplained.
A joke might account for the correspondence. It did not account for a mathematical correction whose significance she herself had only just understood.
Nor did it account for the date.
She took a sheet from the printer and began to reproduce the derivation.
It was an old problem, although her particular formulation was new. The conventional account of personal identity assumed that an observer persisted through a succession of experiences ordered in time. One could question the precise nature of that persistence, but the ordering itself was generally taken for granted.
Émilie had attempted to construct a formal account in which the experienced sequence was not fundamental.
The difficulty was not that such a structure could not be described. Mathematics accommodated many structures that were physically impossible, and some that were merely unfamiliar.
The difficulty arose when she tried to specify what it meant for two observations to belong to the same observer.
If their identity depended upon temporal continuity, the model collapsed into the conventional account.
If it did not, she required another criterion.
She had tried memory, causal dependence, informational continuity and several more elaborate constructions. Each had failed under some transformation of the ordering.
The correction supplied in the letter avoided the difficulty by refusing to treat identity as an independently preserved property.
Two descriptions could be equivalent without requiring that their respective observers be numerically identical.
The distinction was mathematically defensible.
Its philosophical consequences were less agreeable.
One could, in principle, have a collection of experiences possessing all the internal characteristics of a continuous life without there being any persistent subject to whom those experiences belonged.
That proposition was hardly unprecedented. Philosophers had entertained related possibilities for centuries. What interested Émilie was the prospect of expressing the distinction without assuming, at the outset, precisely the identity she was attempting to investigate.
She worked until two.
When she raised her head, the grey folder was no longer on the desk.
She had not heard anyone enter.
She looked beneath the papers, inside the drawers and behind the books. There was no folder.
Nor was there any sign of the page she had examined.
Her own calculations remained.
She felt a brief irritation at the untidiness of the event. It was not yet fear. Fear would have required her to accept that something genuinely inexplicable had occurred, and she was not prepared to grant so much on the evidence available.
She wrote in her notebook:
Document present at 11:00. Absent at 14:03. No witnessed removal.
She considered adding possible lapse of attention.
After some thought, she did so.
The address arrived on Tuesday.
It was written on a second card, delivered in an ordinary envelope bearing a Paris postmark. There was no accompanying message.
The place lay some distance from the city, in a region of low wooded hills and agricultural land. Émilie found it on a map without difficulty. The property was indicated by a narrow private road leading from a minor departmental route to a large rectangular building surrounded by gardens.
There was no name.
She searched the property records available online. The land existed, but she could find no satisfactory account of its ownership. An older survey showed a different arrangement of buildings. A more recent aerial photograph showed what appeared to be the same structure, although its orientation relative to the road was not quite consistent with the map.
She attributed the discrepancy to the usual imperfections of cartographic data.
The postal address was valid.
A room had been prepared.
She found that the second fact interested her more than the first.
It implied either that someone expected her to come or that someone wished her to believe she was expected.
The difference was considerable, but she could not determine which explanation was correct.
On Wednesday she informed her department that she intended to take several days of leave.
Her colleague Laurent Morel, whose professional speciality was mathematical logic and whose personal speciality was the provision of unsolicited advice, expressed surprise.
"You never take leave."
"I've taken leave before."
"Not during term."
"There are no lectures requiring my presence."
"Where are you going?"
"Outside Paris."
"That's unusually vague."
"I haven't decided what to tell you."
He laughed.
Émilie did not.
Laurent looked at her more carefully.
"Is something wrong?"
"No."
"Then why do you look as though you've discovered something unpleasant?"
She considered the question.
"Because I may have discovered something important."
"Those are not ordinarily the same thing."
"They aren't mutually exclusive."
He asked whether it concerned her paper.
She told him that it did.
He offered to read the current draft. She declined, explaining that the work was not yet ready for examination.
It was the truth, although not the whole of it.
Before leaving, she asked him an apparently unrelated question.
"Suppose you were given a complete and internally consistent description of a person, including every memory, sensation and intention. Would that description establish that there was a single subject to whom those experiences belonged?"
Laurent considered.
"Not without specifying what you mean by a subject."
"Quite."
"Are you asking about psychological continuity?"
"I'm asking whether continuity is something we discover or something we impose upon the description."
"That depends on the model."
"Yes."
He regarded her for a moment.
"Émilie, what exactly have you been working on?"
"An equivalence relation."
"Between what?"
She placed her hand upon the folder she was carrying.
"That is becoming less clear."
She travelled on Thursday.
The morning was cold, with a pale sky and a wind that moved the bare branches of the roadside trees without producing much sound. She drove rather than take the train, partly because the property was inconveniently situated and partly because she wanted the option of leaving whenever she wished.
She packed a small case containing clothing for three days, her notebooks, a laptop and the ordinary necessities of travel.
She did not bring a book.
She had the impression, which she recognised as irrational, that there would be books where she was going.
At a service station she stopped for coffee and examined the original invitation once more.
The phrase You are under no obligation continued to trouble her.
It was perfectly courteous. It was also unnecessary.
An ordinary invitation carried no implication of compulsion. The explicit denial suggested that some question of obligation had already arisen, although she could identify no occasion on which it had done so.
She recalled the handwriting on the first card.
You have already been.
She had begun to find the sentence less alarming than its implications.
If the statement were true, then either her memory was defective or the conventional ordering of events did not adequately describe what had happened.
If it were false, someone had constructed an unusually sophisticated deception.
The second possibility remained considerably more probable.
She finished her coffee.
Outside, the afternoon had acquired the peculiar stillness that sometimes precedes snow.
She resumed her journey.
At fifteen minutes before four she turned from the departmental road onto a narrower lane bordered by old chestnut trees.
There was no gate.
The road passed between two low stone walls, continued through a small wood, and emerged before a broad gravel forecourt.
The House stood beyond it.
It was larger than she had expected, built of pale limestone darkened by weather, with a central block and two wings extending backwards towards the gardens. Its windows were tall and regularly spaced. The roof was slate, broken by several chimneys whose arrangement appeared slightly too symmetrical to be accidental.
There was nothing overtly remarkable about the architecture.
Nevertheless, Émilie remained in the car for several minutes.
She could not immediately determine why the building appeared familiar.
It was not resemblance to a place she had visited. She could recall no such place.
It was rather the sensation of recognising an arrangement she had previously understood without ever having seen it.
The House seemed to occupy exactly the position it ought to occupy.
This impression was sufficiently absurd that she dismissed it.
She checked the time.
15:57.
She had arrived early.
The front door opened.
A woman emerged, perhaps sixty years old, tall and slender, with iron-grey hair drawn back from a face of considerable composure. She wore a dark dress of excellent cut and no visible jewellery.
She descended the shallow steps without hurry.
Émilie got out of the car.
"Dr Varenne?"
"Yes."
The woman inclined her head.
"I'm Madame Delorme. Welcome."
Her voice was low, cultivated and entirely without theatrical emphasis.
Émilie shook her hand.
The woman's fingers were warm.
"I hope my arrival isn't inconvenient."
"Not at all."
"I'm a little early."
Madame Delorme glanced towards the House.
"That is not usually a difficulty here."
She spoke as though she were explaining a minor matter of household management.
Émilie looked past her towards the entrance.
There was a table visible in the hall, and upon it a vase of white flowers.
She recognised the table.
For the first time since receiving the invitation, she felt something very close to fear.
Madame Delorme observed her expression without appearing surprised.
"Would you prefer to remain outside for a little while?"
Émilie considered.
"No."
"Very well."
The older woman stepped aside.
"You must understand that nothing is required of you merely because you have come."
Émilie looked at her.
"The letter said something similar."
"Yes."
"Why?"
Madame Delorme appeared to give the question serious attention.
"Because people occasionally mistake being expected for being obliged."
"And am I expected?"
"Of course."
"By whom?"
There was a brief silence.
Not an embarrassed silence. Not the hesitation of someone searching for an appropriate answer.
It was the perfectly untroubled interval of a person who had heard a question that did not apply.
Then Madame Delorme smiled.
"Perhaps you'd like to come inside."
Émilie took her case from the car.
The gravel made a dry sound beneath her shoes as she followed the older woman towards the entrance.
At the threshold she paused.
Beyond the open door lay the hall she had glimpsed from the forecourt. Its floor was of dark stone, polished but not reflective. A staircase rose
at the far end. The table stood exactly in the centre, with its vase of white flowers.
There were seven flowers.
She knew this before counting them.
She also knew, with an immediacy that resisted explanation, that there had been eight when she had last seen them.
Madame Delorme waited.
"Is something the matter?"
Émilie looked at the flowers.
"I think I've been here before."
"Yes," said Madame Delorme.
There was no triumph in her voice, no suggestion that a mystery had been solved.
She said it as one might confirm that a guest had previously visited a restaurant.
Émilie turned towards her.
"When?"
Madame Delorme regarded her with an expression of such unfeigned courtesy that the question suddenly seemed intrusive.
"I don't think," she said, "that you would find the answer helpful just yet."
Émilie might have objected. She might have insisted upon an explanation, demanded to know who had sent the letters, or returned immediately to her car.
She did none of these things.
Instead she crossed the threshold.
The door remained open behind her.
She noticed this particularly.
She had expected, without knowing why, that it would close.
Madame Delorme followed her into the hall and placed one hand lightly upon the table.
"Your room is ready. You may rest before dinner if you wish."
"Thank you."
For the first time the older woman's expression altered.
It was a small change, scarcely more than the withdrawal of a smile.
"Not to the House, please."
Émilie frowned.
"I beg your pardon?"
"You may thank me, if you wish. I have done very little, but the courtesy is understood."
She looked briefly around the hall.
"The House is another matter."
Émilie waited.
Madame Delorme did not elaborate.
After a moment she continued.
"There are a few arrangements you should know about. We shall discuss them when you've settled in. Nothing onerous. You're entirely free to leave, and no explanation will be requested."
"Are there other guests?"
"Residents."
"How many?"
"That depends rather upon what you mean by how many."
Émilie studied her.
It was the first answer that sounded deliberately evasive.
She was preparing to say so when Madame Delorme turned towards the staircase.
"Shall we?"
Émilie followed.
On the first landing there was a tall window overlooking the forecourt. Through it she could see her car standing where she had left it.
She could also see a woman beside the driver's door.
The woman wore a dark coat and held a small travelling case.
For a moment Émilie thought that another guest had arrived.
Then the figure turned.
There was no possibility of mistake.
It was herself.
The woman outside looked towards the House, raised her head and appeared to examine the upper windows.
Émilie stopped.
Madame Delorme, a few steps ahead, stopped also.
Neither spoke.
Outside, the woman opened the car door, placed the case inside and sat behind the wheel.
The engine started.
The car reversed slowly across the gravel and disappeared down the avenue of chestnut trees.
Émilie remained at the window.
She was conscious of her own breathing, the pressure of one hand upon the polished banister, and the quiet presence of Madame Delorme behind her.
She had seen herself leave.
She was equally certain that she had not left.
There was no sensation of division, no vertigo, no displacement of consciousness. She remained precisely where she was, in possession of her memories and her body.
The event had been impossible.
Its impossibility did not make it feel unreal.
After a considerable interval she turned.
"What was that?"
Madame Delorme looked at her with an expression of gentle concern.
"I think," she said, "you've seen something that would be better considered after you've rested."
"That was me."
"Yes."
"Leaving."
"Apparently."
"How can you say that so calmly?"
The older woman lowered her eyes for a moment.
"Would it help if I were less calm?"
Émilie found that she had no answer.
Madame Delorme extended a hand towards the corridor.
"Your room is this way."
Émilie did not move immediately.
She looked once more through the window.
The forecourt was empty.
There was no car.
The sunlight lay across the gravel in a narrow band extending from the western wing. The shadows of the chestnut trees had lengthened. Nothing in the scene suggested that anything extraordinary had occurred.
She became aware, with a sudden and almost intolerable precision, that her desire to remain was stronger than her desire to understand.
This disturbed her more than the sight of herself departing.
Understanding had always been the condition under which she allowed herself to decide.
Here she had already decided.
She turned from the window and followed Madame Delorme down the corridor.
At its far end stood a closed door.
The older woman opened it.
The room beyond was modest and elegantly furnished: a narrow bed, a writing desk, a wardrobe and a single upholstered chair beside a window overlooking the gardens.
There were no pictures.
On the desk lay a notebook identical to the one Émilie had brought.
She approached it.
The cover bore her initials.
She opened it.
The first page was filled with calculations in her handwriting. They continued for several pages, becoming progressively more concise, until the mathematical notation gave way to a single sentence.
There is no one here to receive you.
She stood for some time looking at the words.
Behind her Madame Delorme spoke quietly.
"Dinner is at eight. You may join us if you wish."
Émilie did not turn.
"Who wrote this?"
"I don't know."
"Did you put it here?"
"No."
"Then who did?"
There was a pause.
"I think you'll find," said Madame Delorme, "that we are not always well served by asking who."
Émilie closed the notebook.
She was about to ask another question when she noticed the room's most peculiar feature.
It was not the furniture, the window or the notebook.
It was the absence of a mirror.
There was none above the dressing table, none upon the wardrobe door, none beside the washstand.
She looked around again, uncertain why this omission should matter.
Madame Delorme seemed to understand.
"There are mirrors elsewhere," she said.
"Why not here?"
"We find it preferable that new residents should become accustomed to the room before seeing themselves in it."
Émilie almost laughed.
"That sounds extraordinarily pretentious."
"Yes," said Madame Delorme. "I'm afraid it does."
For the first time, Émilie smiled.
The older woman returned the smile without enthusiasm, as though they had briefly acknowledged an absurdity neither could correct.
"Rest if you can," she said.
Then she withdrew.
The door closed softly.
Émilie was alone.
She placed her case upon the bed, removed her coat, and sat at the desk.
Outside, the gardens extended towards a line of bare trees. Beyond them the land fell away into a shallow valley. There was no movement except the occasional stirring of branches.
She opened her own notebook.
On a clean page she wrote:
Thursday. 16:12.
Then she began to describe what she had seen on the landing.
She recorded the details methodically, avoiding interpretation.
The woman had worn her coat.
The case had been identical.
The car had been hers.
The departure had been observed from an elevated position.
There had been no apparent visual distortion.
She considered the possibility of a double, an elaborate projection, a deception arranged through the architecture of the window.
Each required evidence she did not possess.
She refused to assign probability to explanations merely because they were available.
At the bottom of the page she wrote:
I observed a person indistinguishable from myself departing in my car.
She considered the sentence.
It was accurate.
It was also insufficient.
After a moment she added:
The observation does not establish which of us arrived.
She looked at the words for a long time.
Then, very carefully, she crossed out which of us.
She wrote instead:
whether arrival and departure refer to the same observer.
The correction pleased her.
It was a small thing, but precision remained possible.
She closed the notebook and placed it beside the other one.
Only then did she notice that both volumes were open at precisely the same page.
In the notebook she had found upon the desk, beneath the sentence concerning her reception, someone had written another line.
It had not been there before.
You are free to leave.
Émilie looked at it.
Then she looked towards the window, the door, and the quiet room in which she had been placed.
There was no lock upon the door.
No one had taken her keys.
No one had demanded a promise.
She understood that she might rise, collect her case, walk downstairs and depart.
The possibility was perfectly clear.
She remained seated.
After a while she opened the notebook again.
Below the sentence she wrote, in her own hand:
I know.
And for reasons she could neither explain nor defend, she felt an immense and almost grateful relief.
She did not yet know that gratitude was among the things the House would ask her to relinquish.
Nor did she know that there would be no one to whom the relinquishment could be offered.
For the present, she was content to remain.
Outside, the afternoon continued.
Or appeared to.
End of Movement I: The Invitation