An Affair of Poisons

An Affair of Poisons

Addie Thorley


for believing in me before I believed in myself.


who sat with me through every word.


Paris, 1679


My laboratory reeks of death. Not of blood and flesh and decay, but the garlicky bite of arsenic, the musty essence of hemlock, and the sweet smell of oleander—like rose water and citrus. The lethal perfume tickles my nose as I rush about the hearth, stoking the fire and whisking the steaming concoction in my cast-iron kettle.

Today I will kill a man.

Not directly, as I won’t be the one to tip the poudre de succession into his wine, but my hands made the poison, so I suppose I am responsible in part. This should probably strike fear into my bones or make me tremble with remorse or, if nothing else, have me worried for my soul, but a smile bends my lips as I add a pinch of sulfur to the draught and watch the garish yellow particles flutter down like snowflakes. Sinking and swirling and vanishing.

While the mixture bubbles, I return to the sideboard and thumb through my notes. Is it belladonna or lead I need next? The poison is a new one, called Aqua Tofana. Mother acquired the formula from an associate in Italy. It’s a devilish little brew, rumored to be most effective at disposing of bothersome husbands and rivals at court—one of Mother’s many services.

Some claim she’s a witch. Others a saint. I see no difference; the people of Paris worship her either way.

Behind me, the potion hisses, hungry for the next ingredient. I pick through a bowl of dried belladonna, grind the darkest, most potent berries, and tip the powder into the pot, adding an extra scoop for good measure. I’ll spare no mercy for a lecherous toad like the Duc de Barra. Not when I’ve seen the purple bruises marring the duchesse’s arms and that ghastly cut across her cheek. Not when I’ve heard her wailing from Mother’s salon, recounting how the duc beat their son near to death for attempting to shield her.

Gritting my teeth, I raise my spoon like a dagger and plunge it into the cauldron. Beads of sweat trickle down my face, and my woolen dress clings to my chest, but I stir with ruthless vigor until the concoction reduces into a shimmering crystalline powder. Careful not to touch a speck of it, I spoon the poison into a phial and bury the cork with the heel of my hand.

De Barra’s death will not be quick or painless. I made certain of that. His reckoning will burn like fire down his throat and eat like maggots through his flesh. He will see red, breathe red, bleed red until not a drop of life lingers in his veins. Until he’s cold and stiff, lying facedown on his parlor rug.

Ordinarily, I take no such pleasure in death—I can count on one hand the number of times I have provided poison to Mother’s clients—but if ever I were to relish the role of reaper, this is one such occasion.

Au revoir, Monsieur le Duc.

I situate the phial on a tray and return to the hearth, where my more innocent elixirs are boiling. The largest cauldron holds an elderberry infusion to counteract headaches; the one beside it contains a watercress and fennel seed hunger tonic, which we distribute to the beggars on the rue du Temple when the rutting Sun King fails to issue rations; and the hanging copper teapot brims with a valerian root extract that smooths even the deepest wrinkles.

A little something for everyone. That’s the Shadow Society’s promise. And Mother will have my head if her order isn’t ready by sunup, when her consultations begin. Which will be any moment now, judging by the pale gray light streaming through the shutters, casting ladder-like shadows across the floor. My heart leaps into my throat and my hands flutter like frantic birds as I dash from pot to pot. I was so absorbed with the Aqua Tofana I paid little heed to everything else.

I dip a finger into the plum-colored elderberry infusion and wince—still cold and clotted—and when I peek inside the copper teapot, a sticky, sour-smelling syrup spatters my face.

Merde. I can already hear Mother hissing her customary diatribe. Don’t you care for the cause, Mirabelle? For the people of this city? Who will succor them if we do not? Surely not the glorious Sun King. If it were left to him, the better half of the kingdom would die of pox and he’d be glad of it. Then he could reallocate the funds he uses to put moldy bread in our bellies to build more gilded palaces like that monstrosity at Versailles.

Mother’s intensity may be overwhelming, but her goals are admirable. We are the saviors of Paris. And if I want her to respect me and trust me and welcome me into her inner circle, I must prove I am more responsible than Father.

“Gris, I need the watercress now!” I bellow over my shoulder. He’s hunched over the ancient claw-foot table in the center of the room, furiously chopping herbs. The laboratory isn’t large—it’s a one-room garden house with crooked shelves built into the stone walls—but it’s more chaotic than a battlefield. Curtains of steam hover about our heads, thick as cannon smoke, and the rumble of the bubbling cauldrons sound like a hundred marching feet. I can hardly hear myself think.

I cup my hands around my mouth to call out again, but Gris leans over me and sweeps the herbs into the appropriate pots. Then we stand there, watching, as the bubbles devour the tiny particles. “I added a pinch of butterbur to the elderberry infusion,” he says. “It should come into effect twice as quickly. And three sprigs of rosemary to the wrinkle salve. Now it doesn’t smell like feet.”

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