She reaches toward the highest stone shelf, her blind face tilting upward. A small bottle rests there, crafted from pitch-black glass and sealed with wax the color of dried blood. Her long, skeletal fingers close around it.
"The Abyssal Draught," the witch whispers, holding the vessel between us. "I distilled this poison from the black bile of a rotting Leviathan. It thickens the thin blood of a Vael. It hardens the soft skin. It slows the frantic heart until the muscle beats but once a minute."
She holds the black bottle out to me, the glass cool and heavy in the water.
"It will let you survive the crushing pressure without acclimation," she says, her voice dropping to a conspiratorial hiss. "It will let you hunt in the dark without the silence breaking your mind. It will make you strong. You will be stronger than any betta in the history of the Reef."
"Give me the bottle."
My hand reaches for the glass, fingers closing around the cool, smooth surface.
Oona snatches it back, her movements surprisingly swift. "The price, little guard. The price is heavy."
"Name your price."
"The draught borrows strength from your own future," Oona explains, her blind face turned toward me. "It takes your time. When the dark magic fades from your veins, you must pay the borrowed years back. The debt collects all at once. You will return to this cave. I will bleed you. The aged, magic-soaked sludge in your veins makes a rare base for my brews. Your ruined blood is my price."
I stare at the black bottle, the weight of her words pressing down on me like the water above.
If I drink this poison, I am shortening my natural life. I am surrendering decades of my future. When I return to the Witch, I will be old. I will be broken. I will be withered and weak.
Vaelis surfaces in my mind. His bright golden eyes, wide with terror. Trapped in the dark. He is bleeding. He is waiting for his best friend to fulfill her oath. I promised to protect him. I told him I would save him.
I am the only one coming for him.
"Give me the bottle," I demand, my voice cold as the abyss itself.
Oona hands the glass to me, her long fingers brushing against mine. "Drink the liquid quickly. It tastes like drowning."
I break the wax seal with my thumbnail, throwing it into my satchel. I lift the bottle to my lips and drink the poison, the liquid coating my throat with an oily, metallic taste that promises oblivion.
The poison does taste of drowning. Cold as the abyssal trench, it burns a path down my throat and turns my stomach to solid ice.
My grip spasms. The black bottle slips from my fingers, shattering against the stone floor of the cave. I gasp, a ragged, useless sound.
My heart hammers against my ribs—a frantic, desperate rhythm. One. Two. Three.
Then it stops.
A terrible, agonizing pressure crushes my chest. The frantic beat returns, but it is slow. A ponderous, heavy crawl.
Thud.
I wait, frozen in the suffocating silence of the cave.
Thud.
The oppressive dark of the cave brightens. My soft skin tightens, hardens into something resembling leather cured in the sun. The blue veins on my hands stand out, stark and black, pumping sludge instead of blood. A heavy, invincible weight settles deep into my bones.
"Go," Oona whispers from the deep shadows of her cave. "Leave before you forget which way is up."
I turn from her domain. I swim from the dark cave.
I return to the hidden skiff.
I climb inside the cockpit, my movements stiff and alien in my new body. I seal the heavy hatch. The controls are small and fragile in my hardened hands.
I turn the skiff around.
