The moment the Blacks were out of sight, "Tom Riddle" let his shoulders drop.
His stolen face rippled.
"Okay," Nico muttered in his own voice, low and annoyed. "Step one: don't die. Step two: don't get worshipped into unpaid overtime. Step three: find more hot adults."
He slipped into an empty side corridor, checked there were no lurking Death Eaters around the corner, then let the mask go.
Skin liquefied.
Robes sagged.
A second later, "Lord Voldemort" collapsed into a slumping puddle of crimson goo veined with yellow lightning.
Nico sighed in relief, spreading himself out across the stones.
"Much better. Faces are exhausting."
He left a thin humanoid shell nearby, forming it out of barely enough mass to pass casual inspection if anyone came snooping. A decoy.
The rest of him oozed up the wall and vanished into the cracks.
> Bellatrix: 5% installed.
Me: 95% available.
World: full of possibilities and asses.
He wiggled along the ceiling, following the faint tug of Tom's memories.
Diagon Alley.
Busy. Crowded. Good place to people-watch and possibly climb inside them.
He gathered himself in a trembly blob, grabbed the wand he'd kept inside his own mass, and thought very hard:
> Apparate, Diagon Alley, but like… discreetly, please.
Magic flowed.
Nico vanished with a crack that sounded only a little like someone slapping jelly.
---
He reappeared halfway up a brick wall in a narrow passage off Diagon Alley, stuck there like something thrown and forgotten.
"NAILED IT," he shouted, then remembered stealth. "I mean. Nailed it quietly."
He slid down the wall, becoming a smear, then a puddle, then a thin invisible layer spreading across cobblestone.
Diagon Alley buzzed all around him.
Voices. Footsteps. Owls shrieking in their cages. The smell of parchment, ink, sugar, and bad budgeting.
He let himself ride the flow of bodies, a film of goo clinging to boots and hems, hopping from robe to robe like the world's horniest, least responsible parasite.
> Adult, adult, child, child, child, no, ew, no, that one smells like cabbage, no, that one is 90… respect, but also no…
He paused on the hem of a witch's robes and peeked around the corner of a display.
Madam Malkin's. Kids on stools. Pins everywhere.
Absolutely not. He was banned from being anywhere near rows of teenagers and fabric. That way lies prison and system prompts.
He flowed on.
Further down the Alley, the shops got shabbier. Less polished marble, more peeling paint. Secondhand books. Slightly dangerous potion ingredients. Robes that had seen several lives already.
A raised voice snagged his attention.
"…I said it's fine, Sev."
The voice was female. Tired. Dry. Cutting.
He slid toward it.
Out in front of a secondhand robe shop, a thin woman stood with a boy at her side, a paper list in one hand and an expression that said she'd run out of patience six years ago and never got it back.
Dark hair pulled back in a rough knot. Hooked nose that ran in the family. Robes mended three different ways. Lines at the corners of her mouth that had nothing to do with age and everything to do with stress.
Eileen Prince.
Nico recognized the name from Tom's memories.
Half-blood. Old family. Poor choice of husband.
The boy next to her had lank black hair, too-long clothes, and the kind of hunched shoulders you got from hearing "don't talk" more than "how are you".
Severus. Future greasy bat. Currently: awkward skinny teenager with a first-year list clutched in his hand.
"Ma," he said quietly, "we can wait. I can use the old robes."
"You're not going to Hogwarts in things that don't fit," Eileen snapped back, then rubbed her forehead like the reply hurt her. "You'll get what you need."
She glanced at the price tag in the shop window and visibly recalculated her life choices.
Nico watched them from the cobblestones, tasting their magic.
Severus: sharp, coiled, vicious under all that awkwardness. A dagger trying to pass as a spoon.
Off-limits.
Eileen: older, dulled by repetition, but her power was still there. Buried under exhaustion, resentment, and too many compromises.
Grown woman. Strong. Angry. Protective.
> Host.
He vibrated.
> MILF host.
He slid closer, hugging the shadow under the door as they stepped inside the shop.
A cracked bell jingled overhead.
Secondhand robes hung in limp rows, sorted by size and number of suspicious stains. The shopkeeper, an old witch with a measuring tape around her neck, squinted at them.
"School set?" she asked.
"Yes," Eileen said shortly. She handed over the list. "Fifteen-year male, standard kit."
Severus fidgeted.
Nico climbed the back wall, slipping up past dusty shelves, watching.
Three minutes of measuring later, the boy was on a crate while the witch searched for something close to his size.
Eileen stood near the front mirror, arms folded, eyes distant.
Tired. Cornered. Still sharp enough to hate both of those facts.
Nico's goo quivered up near the ceiling.
He didn't think about strategy.
He thought:
> Sad hot woman… deserves better outfit.
And dropped.
---
He fell like red rain.
Not visible, not to normal sight. Just a shimmer of wrongness sliding down the mirror, splattering against the floor, then surging up under the nearest battered mannequin.
The mannequin wore a black dress-robe on a "CLEARANCE" rack, ugly as sin but structurally sound.
Nico flooded it.
Fabric twitched.
Seams tightened.
The ugly robe smoothed itself out like it had taken offense.
Eileen noticed.
Her eyes narrowed.
The clearance robe on the mannequin now looked… less pathetic. Darker. Lines cleaner. The fall of it suddenly flattering, the cut a little sharper, neckline a hint more daring, waist a hint more defined.
"New batch, are they?" she asked the shopkeeper, suspicion automatic.
The old witch glanced up. "Mm? No. Same tat as yesterday."
Eileen frowned at the robe.
The robe, very subtly, looked back.
Nico held himself together, trying to stay "clothing that exists" and not "thing that talks".
> Approach. Seduce. Do not slime the child. Focus.
He loosened his hold just enough for the robe to sway on the hanger like it had caught a draft.
Eileen's eyes followed the movement.
Her jaw shifted.
"You're not here for you," she told herself under her breath. "Idiot."
Still, she stepped closer.
Her fingers brushed the fabric.
Nico nearly purred.
Her magic snapped against him like a live wire under calloused skin.
Old Slytherin. Half-blood. Sharp as broken glass once upon a time. Life hadn't done her any favors, but she had not rolled over and died.
He liked that.
He pushed a little of himself forward, making the fabric feel cool and smooth under her touch, just the right kind of heavy.
The old witch looked over. "Good eye," she lied. "That one's… erm… sturdy."
"How much," Eileen said, already frowning, doing the arithmetic on rent, food, books, and being constantly screwed by existence.
"For you? Five galleons."
Eileen stared.
"That's not a 'for you' price," she said flatly.
The woman backpedaled. "Three, then."
"Two," Eileen snapped.
"Three and I fix the hem and seams," the witch countered.
"Two and you stop pretending it's worth more than that," Eileen said.
The witch looked like she wanted to argue on principle, then looked at Eileen's face and decided not to.
"Fine."
Eileen dug around in the small purse she had tucked in her robes, counted the coins like each one hurt, and tossed them across.
"Bag it," she said.
Nico almost cheered.
> Step one: acquired.
The robe came off the mannequin. Nico clung to it, compressing his mass, staying thin, folded, non-suspicious.
"Ma?" Severus called quietly from the back. "She found one that fits."
"I'm coming," Eileen said.
She slung the new robe over her arm, the weight of it settling against her.
Nico slid, just a little, to rest where her hand gripped the fabric. Just enough contact.
Cold-sharp magic nipped at him.
He nipped back.
Her fingers twitched.
She paused.
Turned her head, as if listening.
Then shook it off and went to see her son.
---
They left the shop ten minutes later.
Severus had a robe that fit almost right and a small, guilty smile he tried to hide by ducking his head.
"Say thank you properly," Eileen said.
"Thank you," he said to the shopkeeper.
"I meant me," she added.
He huffed, small and awkward. "Thanks, Mum."
She grunted something that might have been acceptance and nudged him toward the door.
Outside, the Alley was busier.
Severus' eyes drank in every wand, owl, and spell in the air.
Eileen's eyes were on their budget and the sun's angle.
"We still need your potions things," she muttered, scanning the list. "And a cauldron. And—"
She juggled the bag of his robe and the wrapped bundle that was hers, too distracted to notice when a sliver of darkness seeped out of the cloth and into her sleeve.
Nico moved.
Up her arm.
Cool and electric under the skin, like water where there should only be blood.
Eileen stiffened.
She stopped walking.
"Ma?" Severus looked back.
"Go on," she said. Her voice sounded normal. Her body did not feel normal. "To the apothecary. I can see it from here. I'll be right behind you."
He hesitated.
She lifted her chin in that way that meant do not argue.
He obeyed, slipping into the flow of people toward the potions shop.
Eileen stepped sideways into the narrow shade between two storefronts, out of the direct throng.
Then she grabbed her own wrist, hard.
"What the hell," she hissed quietly. "Get out."
Nico paused.
> Ah. Smart.
A smarter symbiote would have stayed quiet.
Nico was not that.
"Hi," he said.
Out loud.
In her head.
Everywhere.
Eileen froze.
Her fingers dug into her skin.
"Fantastic," she muttered. "I've finally lost my mind."
"You haven't," Nico said helpfully. "You're just being touched by greatness."
She went utterly still.
"Name," she said. Calm. Dangerous calm. "Now. And if you say 'Lord Voldemort' I will cut off my own arm."
"Technically," Nico said, "I ate that guy, so he's more like a roommate I shit out."
Silence.
Eileen slowly turned her head and banged it once, very lightly, against the wall behind her.
"This is my punishment," she muttered. "For marrying a Muggle. For ever leaving the Prince library. This is it."
Nico pulsed faintly under her skin.
"Okay, rude, but also, hi," he said. "I'm Nico. I'm a goo. I make clothes. I do armor. I kill ugly wizards by accident. You have great potential and also a fantastic wrist."
She stopped mid-eye-roll.
"...A goo," she repeated.
"Yes."
"Sentient slime," she clarified.
"High-functioning sentient slime," he corrected. "With fashion sense."
She closed her eyes for a second. "Where exactly are you."
"Everywhere," he said happily. "But specifically? Right now? Under your skin from here to here."
He traced a path along her forearm.
Her muscles twitched under his touch.
She felt the path. Cold, prickling, then warm where he settled.
"You're a parasite," she said.
"Rude," he said. "Symbiote. I give benefits."
"Like voices in my head?"
"Like protection, power, a hot new wardrobe, and the ability to break someone's arm through polite handshake," he said promptly. "Also, heels."
"Heels," she repeated flatly.
"And a choker," he added. "Non-negotiable."
She considered just walking into Knockturn, finding the nearest curse-breaker, and seeing who exploded first, her or the thing stuck to her nerves.
Instead, she asked, "What do you want."
"Hosts," he said cheerfully. "Plural. I'm already renting a murder girl. But she's busy being fanatical. You look more… stable. And hot in a depressed algebra teacher way."
"Try that sentence again without dying," she said coldly.
"Sorry. You look like you deserve better than cheap robes and a useless husband," he said. "And you're sending your kid into a castle full of monsters with nothing but old textbooks and spite. Which, respect, but I can help."
That hit.
She hated that it did, but it did.
Her eyes flicked toward the direction Severus had gone.
"You don't touch him," she said.
"Not a drop," Nico said instantly. "No kids. Rule in my contract. You, though…"
He let the robe on her arm flex slightly, threads tightening, fabric shifting so it rested just right.
"You could be dangerous again," he murmured. "Like you were at school. Before life sat on you."
She inhaled sharply.
Memories she hadn't invited surfaced: green sparks, duels, sharp smiles across Slytherin tables. The Prince library. Being feared, just a little.
Not this.
Not counting Sickles while her husband ranted.
"How long have you been in me," she asked.
"Like sixty seconds?" he said. "You're my second proper anchor. I split myself. One piece in the fanatic, one in you, some of me free to slime around."
She had no context for "fanatic" and didn't like the sound of it.
"Benefits," she said. "Specific, not vague."
He perked up.
"Okay," he said. "I can harden around you. Armor. I can shift to clothes. Any clothes you want. I can boost your spellcasting a bit by lending mass and weird soul stuff. I can sense incoming attacks, poisons, some hexes. Also I can make you look incredible in basically anything."
"You sound like a pervert's idea of a warding charm," she muttered.
"Accuracy is not an insult," he said.
"Cost," she said. "Those things always cost."
"I eat magic and vibes," Nico said honestly. "And occasionally other people, but I'm trying to pace myself. I don't eat you. Just… ride along in your system. If you die, that's awkward, so I prefer you don't."
"You killed someone before this," she said.
"Technically, yes," he said. "He had it coming. Also he was ugly. Also I panicked."
Her eyes narrowed. "Name."
Nico hesitated for three full seconds, then said, too brightly, "I feel like we've really bonded emotionally already and names are a lot of pressure."
"Name," she repeated.
"...Voldemort," he muttered.
She stared.
Then, to Nico's horror, she laughed.
Not a nice laugh. Harsh, surprised, the sound of someone who'd run out of proper reactions.
"You killed the Dark Lord," she said. "By accident."
"Look, he teleported in front of me while I was flying through dimensions," Nico complained. "I was an object in motion. He was in the way. Physics happened."
"You cut him in half," she said.
"Yes."
"And then you ate him," she said.
"I was scared and hungry," Nico said. "It was a stressful day."
Her hand tightened on her own wrist.
"Show me," she said.
He blinked.
"In public?"
"Here," she said. "Now. Something small."
He obliged.
The robe she'd bought shifted.
Threads reknit. The ugly cut narrowed, straightened, the fabric darkening to a richer black with a faint sheen. A subtle high collar rose at the neck, snug but not choking. The sleeves cleaned up. The hem corrected itself.
Around her throat, the air thickened into a slim, smooth band: a black choker shaped out of nothing, resting against her skin like it had always belonged there.
He let a suggestion of heel form in her boots: just enough lift to change her stance.
Eileen glanced at the nearest dusty window.
Her reflection stared back: same face, same lines, but framed better. The robe fit. Her posture looked less defeated, more dangerous. The choker turned "tired mum" into "do not test me."
Her magic hummed in agreement.
She exhaled.
"You're insane," she said.
"Correct," Nico said.
"You're dangerous."
"Also correct."
"And you're offering me power in exchange for being your… landlord."
"Host," he corrected.
"Landlord," she repeated.
It was close enough.
He quieted, letting her think.
People flowed past the little shadowed gap, busy with their own preparations, none of them noticing the woman pressed to the wall talking to her own veins.
"You stay off my son," she said finally.
"Off," he agreed.
"You don't control my mind."
"I can't," he said. "I'm not that kind of monster. I annoy, I tempt, I accessorize. That's it."
"You don't betray me for whoever you had before me," she said.
"Fanatic girl?" he said. "Different contract. You'd hate each other. It'll be hilarious."
She actually snorted.
"If you're lying, I will find a way to kill you," she said calmly. "Even if you're glued to my arteries."
"Honestly," Nico said, "that's kind of hot."
She ignored that.
"You keep him safe when you can," she added, voice flattening. "You see something I don't, you warn me. You don't use him. You don't drag him into your schemes. You help me get him through that school alive, and I'll carry you."
Nico went very still under her skin.
"You're bargaining with a slime monster," he said.
"I was a Prince before I was a Snape," she said. "We bargained with worse."
He thought about Bellatrix, with her delighted "I belong to you" and wild worship.
He thought about Eileen, here, taking inventory of her own doom and haggling with it anyway.
He liked both, for very different, very stupid reasons.
"Deal," he said. "You get the kid through school, I get to be the hottest coat in the castle."
"Robes," she corrected.
"And heels," he insisted.
"We'll discuss the heels," she lied.
He pulsed once, sealing the bond along her arm like liquid lightning solidifying into a subtle band.
She felt it lock, not as a brand, but as an extra layer.
Not hers.
Not not hers.
"Ma?" Severus' voice floated from the street, anxious. "Where are you?"
Eileen pushed off the wall.
"Coming," she called back.
When she stepped out of the shadows, her son stared.
His eyes flicked down to her robe, her boots, her posture.
"You look…" he started, then shut down the compliment halfway.
"What," she said.
"Different," he finished. "Good."
She resisted the urge to touch the choker.
"Must be the light," she said.
Nico hummed smugly against her skin.
> Step one: new host.
Step two: Hogwarts access package acquired.
Step three: survive long enough to enjoy it.
As they walked toward the apothecary, he stretched carefully along Eileen's spine, tasting the world from a new vantage point, feeling her anger and tired love and sharp old pride.
Bellatrix burned hot, like a bonfire.
Eileen burned low and steady, like coals waiting for an excuse.
Nico curled deeper into both his anchors, pleased in the dumb, greedy way only a lustful idiot goo could be.
He'd killed a Dark Lord by accident.
Now he had a fanatic in one hand and a bitter genius mum in the other.
What could possibly go wrong.