2. The Arsenic Shopping List

The apothecary's shop on the Rue des Capucins occupied a narrow storefront between a wigmaker and a dealer in ecclesiastical candles, its single window cluttered with glass jars of leeches, ceramic pots labeled in spidery Latin, and a stuffed crocodile that had been suspended from the ceiling so long that its scales had faded to the color of old parchment. The sign above the door read "Charbonneau & Fils, Herboristes-Chimistes," and the bell that jangled when Rolanda pushed open the door was made of tarnished brass and had probably not been polished since the Restoration.

The interior smelled of camphor and gentian root and something else, something sharp and mineral that caught at the back of the throat. Rows of wooden drawers lined the walls from floor to ceiling, each fitted with a porcelain knob and a handwritten label. Behind the counter, a man of perhaps sixty years looked up from the mortar in which he had been grinding a substance the color of dried blood.

"Monsieur Charbonneau," Rolanda said, and the apothecary's face rearranged itself into an expression of professional welcome.

"Madame McAnally. Your usual preparation of valerian and chamomile, I presume? The nervous condition has not improved?"

"On the contrary. The nervous condition has provided an excellent education."

The apothecary's hand paused above a drawer labeled Valeriana officinalis. There was something in her tone that he had not heard before—a note of irony, perhaps, or self-mockery, or something else entirely. He turned to study her face, and what he saw there caused him to set down the mortar with the care of a man who suspects that the object in his hands has become more dangerous than it appears.

"The education of the nerves," he said slowly, "is a subject on which I possess considerable expertise. Might I ask what Madame has learned?"

Rolanda did not answer immediately. She was looking at the crocodile, whose glass eyes caught the light in a way that suggested it had been watching her since she entered. Then she removed a folded paper from her reticule and placed it on the counter between them.

It was a list, written in her own hand—a list she had compiled over three weeks of careful reading in the public reading room of the Bibliothèque Municipale, where she had claimed to be researching the history of Lyonnaise silk production for the edification of the Commissar's household. The librarian, a desiccated man who smelled of boiled cabbage, had been happy to fetch volumes of the Encyclopédie Méthodique and the Dictionnaire des Sciences Médicales without asking why a policeman's wife should need to consult the section on toxicologie.

The list contained twelve substances. Eleven of them had lines drawn through them. The twelfth was circled.

"Digitalis purpurea," Charbonneau read aloud. His voice had changed; the professional welcome had given way to something more guarded. "Foxglove. An infusion of the leaves is used in the treatment of dropsy, though the dosage must be carefully controlled. The active principle is not well understood, but the effects on the heart are—" He stopped. "Madame, this is not a remedy for nervous conditions."

"I did not say that I wished to purchase it as a remedy."

The silence that followed was filled by the ticking of a clock that Rolanda had not noticed before, mounted on the wall behind the counter, its pendulum swinging with the slow regularity of a heartbeat. The apothecary's hand had moved to rest on the counter, and his fingers were very still.

"The sale of digitalis is subject to certain regulations," he said. "The Commissar of the Second Arrondissement is particularly vigilant regarding substances that might be—"

"The Commissar of the Second Arrondissement," Rolanda said, "is my husband."

She had calculated the effect of this statement with the same precision she had applied to her reading list. The apothecary's face underwent a series of rapid expressions—surprise, recalculation, and finally something that looked very much like fear.

"Then Madame will understand," he said carefully, "why I must be especially scrupulous in my compliance with those regulations."

"Of course. I should expect nothing less." She drew a second paper from her reticule, this one bearing the letterhead of the Hôpital de la Charité and the signature of a physician whose name she had copied from a directory of medical practitioners. The paper was a prescription for digitalis, written for a patient named Madame Louise Moreau, who was said to be suffering from a cardiac insufficiency of a chronic nature. "I believe this should satisfy the regulatory requirements."

Charbonneau examined the prescription with the attention of a customs officer inspecting a passport he knows to be forged but cannot prove. The paper was genuine hospital stationery—Rolanda had acquired a sheet of it during a visit to the charity ward, where she had distributed alms on behalf of the Police Benevolent Society and had helped herself to the contents of an unattended desk. The signature was a reasonable facsimile of the physician's hand, based on a sample she had found in a medical journal. The patient did not exist.

"The dosage indicated here is quite... substantial," Charbonneau said.

"The physician assured me that Madame Moreau's condition is severe."

"And the physician's street address is not included on this prescription."

"An oversight, I am sure. Shall I have the prescription returned to the hospital for correction? I am happy to wait."

She smiled, and the smile was the one she had perfected over seven years of marriage to Edmond McAnally—the smile of a woman who has all the time in the world, because time is the only currency she has ever been permitted to accumulate.

Charbonneau looked at the smile, and at the prescription, and at the crocodile that seemed to be listening to their conversation with reptilian patience. Then he turned to the row of drawers behind him and withdrew a small glass vial containing a dark green powder.

"Madame will understand that I must record this transaction in my register," he said. "The name of the patient, the name of the prescribing physician, the date of the sale."

"Naturally. I should expect nothing less from an establishment of such integrity."

He wrapped the vial in brown paper and tied it with string. His hands were steady, but there was a tightness around his mouth that suggested he was performing a calculation of his own—weighing the risk of offending the Commissar's wife against the risk of facilitating whatever the Commissar's wife intended to do with a substance that, in sufficient quantity, could stop a human heart.

"Madame is aware," he said, not looking at her, "that the leaves of digitalis are most potent when dried and reduced to powder. That the powder dissolves readily in liquid. That the taste is bitter but easily masked by strong wine or dark chocolate. That the symptoms of an... overdose... resemble those of a natural apoplexy."

"I am aware of nothing of the sort," Rolanda said. "I am merely a woman with a nervous condition, collecting a remedy prescribed by a physician."

She placed the coins on the counter—exact change, which she had calculated in advance—and slipped the wrapped vial into her reticule. The bell jangled as she departed, and the sound seemed to Charbonneau to have the quality of a warning that he had failed to heed.

The weeks that followed assumed a pattern that Rolanda came to think of as her second education.

She had been educated once before, at the Convent of the Visitation, where the sisters had taught her to embroider, to play the pianoforte with moderate competence, and to read well enough to appreciate the less objectionable passages of Scripture. They had not taught her botany, or chemistry, or the legal rights of married women under the Civil Code. They had not taught her that foxglove grew wild in the foothills of the Monts du Lyonnais, or that its leaves were most potent when gathered in the early summer, just as the flowers began to bloom. They had not taught her to dry the leaves in a cool, dark place, or to reduce them to a powder so fine that it vanished into liquid like a ghost into fog.

These things she taught herself, in the small hours of the morning when Edmond was at the Prefecture and the servants were occupied with their duties and she was left alone in the stillroom that had once belonged to Edmond's mother, a woman who had died before Rolanda's marriage and whose memory was preserved only in the rows of empty jars and the faint scent of lavender that still clung to the walls.

The stillroom became her laboratory. She justified her presence there by claiming an interest in the preparation of household remedies—a pursuit that the cook considered appropriately domestic and that Edmond considered beneath his notice. She made rose water and orange flower water and a very passable tincture of lavender. And in the afternoons, when the household was quiet, she worked with the digitalis.

She learned that the powder could be graded by color: the palest green for the mildest dose, the darkest for the strongest. She learned that a solution of the powder in distilled water remained clear and odorless for up to three days before beginning to cloud. She learned that the bitterness could be concealed by the tannins in red wine, by the sweetness of chocolate, by the pungency of a sauce of capers and white wine such as the cook prepared for Edmond's veal.

She kept a journal, written in a cipher of her own devising—a system of symbols that combined the botanical abbreviations she had found in the Encyclopédie with a private shorthand that no one else could read. In this journal she recorded her experiments: the weight of powder, the volume of liquid, the time to dissolution. She recorded the effects of various dosages on the household pests that she trapped in the cellar and brought to the stillroom in a covered basket. She recorded her observations with the detachment of a chemist and the patience of a saint.

And as she worked, she continued to play the role of the Commissar's wife.

She appeared at Edmond's side for the receptions at the Prefecture, dressed in the dove-grey merino or its successor, a gown of aubergine silk that had cost thirty-seven francs and had been described by the Préfet's wife as "most retiring." She smiled at the appropriate moments, laughed at the appropriate pleasantries, and offered no opinion on any subject more controversial than the weather. She visited the sick of the parish with baskets of soup and bandages, and she attended Mass every Sunday in a pew near the back, where she could observe without being observed.

And on the first Tuesday of each month, she visited the Caisse d'Épargne de Verrières, where a discreet clerk named Monsieur Tavernier received her deposits with the gravity of a confessor and never once inquired about the source of the funds.

The income from Saint-Rambert was not negligible. By the end of May, Rolanda's account contained two thousand three hundred and forty francs—a sum that represented roughly one-third of Edmond's annual salary as Commissar. It was not enough to live on indefinitely, but it was enough to leave on, if leaving became necessary. And it was enough to finance the acquisition of certain materials that were not available from the obliging Monsieur Charbonneau.

The arsenic she obtained from a tinker who passed through Verrières in the third week of May, selling pots and pans and, for a small additional consideration, a paper twist of white powder that was guaranteed to rid a household of rats. The tinker had a face like a wrinkled apple and the shrewd eyes of a man who had learned that the law was something to be negotiated rather than obeyed. He did not ask why a lady in silk wished to purchase rat poison, and Rolanda did not offer an explanation.

The belladonna she grew herself, from seeds obtained through a seed merchant's catalogue that she had ordered under the name of her maid. The plants thrived in the shade of the garden wall, their dark berries ripening in the summer heat, and Rolanda tended them with the devotion of a mother. She harvested the berries at night, by the light of a shuttered lantern, and she processed them in the stillroom while the household slept.

But it was the digitalis that remained her principal study, the instrument on which she practiced her scales like a musician preparing for a concert that had no announced date.

She learned, through careful questioning of the cook, that Edmond had developed a taste for mushroom ragout. The mushrooms were gathered in the forests near Saint-Rambert—a coincidence that Rolanda noted in her cipher journal with a small, precise symbol that represented the intersection of two lines of inquiry. The cook prepared the ragout on Fridays, when the fishmonger's delivery was unreliable, and Edmond consumed it with the appetite of a man who had never doubted that the world would provide whatever he desired.

On the second Friday of June, Rolanda offered to assist with the preparation of the ragout.

The cook was surprised—Madame had never shown any interest in the kitchen beyond the daily approval of the menu—but she was also flattered, and she accepted the offer with the condescending graciousness of an expert permitting an amateur to observe. Rolanda stood at the scrubbed pine table and watched as the cook cleaned the mushrooms and sliced them and sautéed them in butter with shallots and parsley. She asked questions about the varieties of mushrooms, about the seasons when each was available, about the signs that distinguished the edible from the poisonous.

The cook was happy to demonstrate. She had been gathering mushrooms since she was a girl in the Morvan, and her knowledge was both extensive and entirely empirical. She could identify a death cap by the color of its gills, a destroying angel by the shape of its volva. She showed Rolanda the mushrooms she had gathered that morning—a basket of cèpes and chanterelles and a single, perfect amanita that she had picked by mistake and set aside for disposal.

"The amanita resembles the edible field mushroom," the cook explained, "but the gills are pure white, and the base of the stem is enclosed in a sac. A single cap is sufficient to kill a grown man. The poison attacks the liver and the kidneys. There is no antidote."

Rolanda examined the amanita with an expression of polite curiosity. The mushroom was beautiful in the way that dangerous things often are—pale and delicate, with a cap like ivory silk and gills like the pages of a forbidden book.

"What does it taste like?" she asked.

The cook looked at her sharply. "No one knows," she said. "Those who have tasted it are dead."

That night, Rolanda made a new entry in her cipher journal. She had been studying the digitalis for its effects on the heart, but the cook's words had opened a new avenue of inquiry. The amanita attacked the liver and the kidneys. The digitalis attacked the heart. The symptoms of each were distinct, and either alone might arouse the suspicion of a competent physician.

But together? Together they might present a picture so confused, so contradictory, that no physician could untangle it.

She wrote the word "combination" in her cipher, and beside it she placed three symbols: the foxglove, the death cap, and a question mark that glowed like a promise.

The afternoon that changed everything was a Thursday in late July, and it began with the arrival of a letter.

The letter was delivered by a messenger in the livery of the Préfecture, and it was addressed to Edmond in the hand of the Préfet de Police himself. Rolanda received it from the maid and placed it on the silver salver in the hall, as custom required, but not before she had examined the seal and noted the urgency of the messenger's manner. When Edmond returned at five o'clock, smelling of tobacco and irritation, he tore open the letter in the hall and read it standing, his jaw tightening as his eyes moved down the page.

"We are to receive a guest," he said. "The Préfet's nephew, a young man named Valcour, has been appointed to the position of Examining Magistrate for the Second Arrondissement. He arrives from Paris next week, and the Préfet suggests that he might lodge with us until suitable quarters can be found."

Rolanda, who had been arranging flowers in a vase of Sèvres porcelain, did not pause in her work. "An Examining Magistrate. That is a position of some importance."

"It is a position that will require careful handling. The Préfet's nephew is said to be ambitious. He is also said to have studied with the Jesuits and to have absorbed their taste for scrutiny. The Préfet advises that we extend him every courtesy."

"Of course. I shall prepare the blue guest room."

"See that you do." Edmond folded the letter and thrust it into his pocket. "And see that you conduct yourself with the dignity becoming to this household. I do not want the Préfet's nephew reporting to his uncle that the Commissar's wife is a woman of—unregulated habits."

He did not specify what these unregulated habits might be, and Rolanda did not ask. She merely nodded, as she always nodded, and continued her arrangement of the flowers. But her mind had begun to work in a way that it had not worked before, tracing the implications of this new variable, this stranger from Paris who would be living under their roof, observing their household, perhaps observing her.

An Examining Magistrate. A man trained by the Jesuits to detect what others wished to conceal.

She placed the last stem in the vase and stepped back to examine the effect. The flowers were white roses and purple irises, and they stood in a harmonious arrangement that pleased the eye while revealing nothing of the mind that had composed it. She thought of the stillroom, of the cipher journal hidden beneath a loose floorboard, of the digitalis powder in its glass vial and the belladonna berries drying on a tray. She thought of the Caisse d'Épargne and the vineyard at Saint-Rambert and the forty hectares that were hers alone.

And she thought of the letter that had arrived that morning, and of the nephew who was coming to Verrières, and of the web of circumstance that was drawing tighter around her with each passing day.

The arrival of the Examining Magistrate, she decided, was not a threat. It was an opportunity. A witness, properly managed, could be made to see whatever the director wished him to see. And a man who prided himself on his powers of observation was precisely the kind of man who could be most easily deceived.

She turned from the flowers and went upstairs to prepare the blue guest room, her mind already composing the scene that would greet the magistrate when he arrived.

Outside, the summer rain began to fall, streaking the windows like the tracks of tears, and somewhere in the distance, a bell was tolling.