"Hand over the Stone, Potter," Quirrel said, bringing up his wand. "You won't like the consequences if you don't." His eyes were bloodshot, and his bald scalp contorted grotesquely as Voldemort stirred underneath.
Harry raised his own wand, but in an instant, it was wrenched from his fingers. He backpedaled until his back bumped the wall, then slid down to the floor. Quirrel sneered as he approached with deliberate, unhurried steps, each exacerbating the burning in Harry's scar.
Harry reached up to clasp his pendant; the memento of his mother always gave him strength. Eyes watering with pain, he prayed for someone, anyone, to save him. Having done this a hundred times back in his cupboard at number four, Privet Drive, he knew it was futile, yet he couldn't help but repeat the silent plea as Quirrel drew ever closer.
"Greetings, little one," a soft female voice said in his head.
The pendant nearly slipped from his fingers. "M-mum?"
The voice laughed. "Mortals called me many things, but never that. You may address me as Lilith. I can help you, but you must do as I say."
"What—"
He yelped as he was flung against the wall. Quirrel flicked his wand, and Harry's pockets turned themselves out one by one until a dark red stone was ejected. It froze mid-air before floating into Quirrel's palm.
"I have it, Master, I have it!" Quirrel exclaimed, holding up the stone reverently.
Harry slumped on the floor, gasping for air. Lilith was speaking again; he struggled to focus on her words through the ringing in his skull.
"There's no time, mortal. The two-souled one is going to kill you now that you're no longer needed. If you want to live, repeat after me..."
"I, Harry James Potter," he said, clutching the pendant for dear life as Quirrel's wand rose to point at him, "vow to yield to you what you desire the most in return for your protection!"
The amulet grew scorching hot, and he let go with a cry. He scrambled to yank it off his neck, only to pause and stare at his left palm. It held an angry red mark in the shape of a pentacle surrounded by a snake eating its tail, but the color was already fading, and the pain receding.
"Good boy," Lilith's voice whispered in his ear, and he shivered at her predatory tone.
The air between him and Quirrel wavered with heat, and space itself split apart, revealing a barren, fiery landscape. Blistering wind washed over him, and a stench of sulfur assaulted his nose. Something—no, someone—stepped through, and the rift closed, bringing relief from the sweltering temperature.
Harry gaped. The stranger was taller than him, older—like the upper-year girls, perhaps—except she wasn't human. Dark bat-like wings extended from her shoulder blades, and a smooth tail protruded through the waistband of her leather shorts, ending with a spade-shaped tip.
Her hair flowed like fire to her bare midriff in waves of rich crimson. Two small horns poked out above the temples, rivaled in length by her pointy ears.
Her strikingly violet, slit-pupil eyes contemplated Harry before swiveling to Quirrel.
"What are you?" Quirrel demanded. "Another of Dumbledore's guardians?"
"I am Lilith," the stranger said, drawing back her arm, "and you are my prey."
"She's not of this world," Voldemort hissed. "Flee, you fool!"
Black flames gathered in Lilith's palm, and she threw them like one would a Quaffle. Quirrel hesitated, half-raising his wand, and it became his undoing: shadowy fire engulfed him, and he collapsed to his knees, screaming in agony.
"Potter, you imbecile!" Voldemort's voice was barely audible over his host's agonized cries. "You have doomed yourself for eternity..."
"Silence, vermin." Lilith kicked the possessed man's head.
Quirrel's neck snapped backward, and he toppled to the floor. A dark shade escaped through the mouth, zooming away with a shriek. The dark flames flared, consuming the corpse in seconds before fading away, only leaving a small pile of ash.
Lilith linked her hands and stretched them over her head with a pleased sigh. Her wings quivered and shrank upon themselves, leaving only faint dark marks on her tan skin.
Turning to Harry, she bared her elongated fangs. She was clad entirely in black leather: skimpy shorts, a tight bodice, and a choker around her neck. Had the situation been different, he might've been flustered about the indecent amount of skin that was on display, but as it was, he could only stare in shock.
"You—you spoke to me through the pendant." His hand rose to grasp it. "Are you... a friend of my mother's?"
Snorting, Lilith tossed her hair back. "Lily and I did make a deal, but I never got her soul. She was a cunning one, your mother... Unlike you."
Harry gulped, recalling what little he knew of the Bible. "You t-take people's souls?"
"A fair price for my services, is it not?" Lilith advanced on him, her smile widening. "Silly boy, there's no point in running away—you already belong to me. Kneel."
Pain lanced through Harry's marked palm, and he dropped to the floor, his body obeying without conscious volition. Lilith sashayed closer; he tried frantically to move his legs, but they didn't budge. His vision blurred with tears.
"You were supposed to protect me!"
"And I did just that, did I not? The fault is yours for not specifying any details. I swear, you mortals are getting dumber every generation." She bent down to grasp the collar of his robes and lifted him to her eye level. A peculiar smell of burning sandalwood and spice tickled his nostrils. "I believe I'll collect my payment straight away. Opening a portal across the planes at a moment's notice was no easy task, even with your unwitting help."
"Let go of me, bitch! You tricked me!" He twisted and punched, but she extended her arm so his swings wouldn't reach her, amusement evident on her face.
She brought up her other hand—slender and feminine but ending in fierce nails—to graze his cheek. "Are you that attached to your useless life, mortal? I would treat you well in the Underworld. Maybe even make you my pet for a time." She licked his blood off her nail, her eyes narrowing.
He ceased struggling and merely hanged onto her wrist so he could breathe. Tears trickled down his cheeks, stinging the fresh cut. "Please don't kill me. Please. I want to live, I have friends, please—"
She let him fall to the floor, where he clutched his throat and coughed. "Tell you what." Her foot tapped the flagstones. "I'll consider letting you off if you manage to amuse me. Beg for your life."
He stared at her for a moment, then lowered his head. "Please spare me."
She yawned theatrically. "Boring. Tell me how worthless you are, worm."
"I'm—I'm worthless," he repeated, choking back tears. "I'm stupid and weak. Please don't kill me."
"Pathetic! Are all mortal children as feeble as you? I made my first kill when I was half your age." She stepped on his head, the heel of her knee-high boots digging into his scalp. "There's no fight in you, no pride! Just for that, I'll make you suffer before I put you out of your misery."