Marinette would never consider herself superstitious. She didn't believe in the supernatural, or the paranormal, or the occult. Anything along those lines would be contributed to an Akuma or other Miraculous means.

That being said, the Agreste manor was sick.

And not in the 90's way a teenager would look at Adrien's rock wall and half pipe and call that 'sick!'

But a real and true illness. Like a body, living and real, suffering with disease.

That phone call on the night she moved in was only the beginning. And it was only because no one had lived there since the murder. No one had been there long enough to witness the strangeness of the house's weird disease.

The first night, the strangest thing was the phone call. After that, she turned Adrien's phone off, surprised it had a charge in the first place, placed it in his room, in his bedside drawer.

Before closing the room up, she stood in its presence, basking in the ambience that was only Adrien.

His smell was still in the room, though stale as it was. Nothing was changed since the day everything changed. The bed wasn't made. There was a used cup on the coffee table. A discarded shirt in the hamper.

No one had been in to clean or pack his things away. Everything stayed exactly the way it was when Adrien was still there.

Before she left the room, Marinette made sure the windows were unlocked. Just in case.

When you hear sweet syncopation

And the music softly moans

T'ain't no sin to take off your skin

And dance around in your bones

The cleaners came three times a week. The manor was just too big to clean in one day, so they broke it up by floor. Monday was the top floor, Wednesday the second, and Friday the first. As the first week went on, Marinette noticed the walls becoming dingy. The gray, textured wallpaper seemed to turn darker, and yellower. Like smoke stains on the walls.

Maybe it had been like that for a while, and she was just now noticing.

On Friday, when the cleaners came to do the first floor, Marinette pointed it out and asked if there was anything they could do about it.

Thankfully, there was, and they stayed an extra two hours to wipe the walls clean.

When they left, the room was looking significantly brighter, and left Marinette in a more optimistic mood.

She tipped heavily.

However, whatever chemicals the cleaners used had backfired horribly, and when Marinette came down for her Saturday morning coffee, huge, disgusting, inky black streaks ran down the walls. It looked like a teenage girl wore too much mascara at prom and got jilted by her date.

"Oh my god!" Marinette shouted, looking around in horror. "What the hell happened?!"

Tikki flew to the nearest stain to examine it. "It stinks!"

Marinette smelled the wall too, and almost vomited. The odor was rancid, like something rotten and foul.

She called the cleaners back in, citing it as an emergency.

The girls came with their standard equipment, only to stop as they surveyed the walls.

"What happened?" Asked the manager.

"You tell me," Marinette tried not to be cross. But there was a tremble of fear in her heart that someone would constitute this as 'redecorating' and she'd lose Adrien's home…and any chance of solving his mystery.

"I've never seen this before," the manager stated firmly. "But we'll clean it right up!"

Marinette watched anxiously as they sprayed on a cleaner and began to wipe.

The rags only smeared the ink around, making the walls blacker and blacker. No matter how many fresh ones, no matter what cleaner they used, the stain just grew bigger and bigger, and more and more foul.

"Stop!" Marinette finally shouted in a panic. "Something is wrong!"

"I agree," said the manager. "I have a mold expert on my team. He identifies stains and all sorts of household growths. I'll call him in."

Marinette could only nod as she glanced around the room in panic. The stains were starting to ooze, and the black growth rolled down like tears.

She moved quickly to remove the decorations from the walls, most not taking any damage from the ooze. She, and the other cleaners moved them into the parlor.

Then, when she went to remove the huge, solemn painting of Gabriel and Adrien from the wall, she watched in horror as the black of Adrien's eyes began to swell, blotting out the emerald green. It seeped into the canvas, spidering out in little lines, until his eyes were completely black…and then it started to run.

"Someone help me take this down!" She yelled, desperate.

Two employees rushed to her, took the painting by the corners, and lifted it from the wall.

The wall behind was completely saturated and looked like tar. It smelled unspeakably bad, and the cleaners staggered away, almost dropping the painting.

Marinette wanted to cry.

For a while, she just stood there, looking at the tar-like substance slowly rolling down the wall in black rivulets. She could hear the cleaners behind her, moving furniture, rugs, anything in the room out of the way. But she just stood frozen, completely enraptured by the poison.

Eventually, she had the sense to call for help. First Nathalie, then Alya, who both said they'd be over soon.

'Soon' didn't seem quick enough as the wallpaper began to bubble and peel off the wall.

"The upstairs all looks fine," someone said. "No black goop anywhere else."

"What did you use to clean the walls?"

"Just white vinegar, which we usually use. I've never seen a reaction like this."

"I couldn't have been the vinegar," said another employee. "Look what was behind that painting. I think our rubbing pushed whatever that gunk is out from behind the wallpaper."

Nathalie let herself in when she arrived, and nearly shrieked in horror as she opened the door.

"What did you do?!"

"I didn't do anything!" Marinette wailed.

The cleaners corroborated her story, and Nathalie seemed to redirect her anger. She touched the wall with her bare fingers and examined the substance.

"I wouldn't do that," said the manager. "We still haven't identified what that stuff is."

"Disgusting. That's what it is." She cleaned her hand with a tissue. "Now, Marinette. I know the clause you were worried about. Redecorating in order to keep the house in pristine condition is what Mr. Agreste would want. We'll replace the wallpaper, and put the paintings in place, and it will be fine."

"Wait," said the manager. "My guy is on his way. Please let him look at this stuff before you make any decisions. He may have to condemn the house."

"Condemn?!" Marinette cried in horror.

"Now," Nathalie said tersely. "We certainly have the money to prevent such a thing from happening. We can replace the whole wall if we have to. Are any other walls in the house in this condition?"

"No, just these in the lobby," said the manager. "Fortunately."

Just then, Alya and Nino arrived, also letting themselves in without knocking. "Hey girl, we made it! What's all this about black—oh."

"Alya!" Marinette cried. "My brand new house is oozing and it's going to be condemned and Mr. Agreste is going to hate me from the afterlife!"

Nathalie scoffed.

"I'm sure it's not…that bad…" Alya trailed off as she noticed the painting on the floor. "Ugh, are you sure someone didn't break in and vandalize the walls?"

"A prank!" Marinette chuckled, a little hysterically. "It's all just a cruel prank by someone with a vendetta! The black goo, the phone calls—"

"Phone calls?"

"Nothing! Never mind!" She laughed a little too harshly, sounding fake to her own ears. "Everything is going to be fine! Yes! Totally fine! Just—just some replaced wall paper…and I'll take care of this!" She grabbed the painting. "Everything will be fine!"

When it gets too hot for comfort

And you can't get an ice cream cone

T'ain't no sin to take off your skin

And dance around your bones

Marinette: Hey Nat, how are you?

Nathaniel: Oh hey Marinette, haven't talked to you in a while. What's up?

Marinette: I have a commission for you. Do you work in paint?

Nathaniel: Occasionally. What's the commission?

Marinette: Can you fix this?

Marinette: [Attachment]

Nathaniel: Umm

Nathaniel: What

Nathaniel: Is this a joke?

Marinette: What? No! When Mr. Agreste passed away, he left the house to me. I think this painting got vandalized last night.

Nathaniel: No joke, it looks super haunted.

Marinette: It's not haunted!

Marinette: So can you fix it?

Nathaniel: I mean, if you can sew up the slashes in the canvas I can.

Marinette: Slashes? What slashes?

Marinette: Omg I didn't even notice that! What the hell!

Nathaniel: I mean, I can probably sew it up too, but I think you'll make it look neater.

Marinette: Ugh, yeah, I'll take care of that. Thank you!

Just like those bamboo babies

Down in the South Sea tropic zone

Bzzt

Marinette bolted upright, hearing the sound of her phone ringing in the darkness. She scrambled around her bed for it, trying to remember where she had left it before she passed out the night before.

Bzzt

She grasped the phone, which had been under her pillow, and looked at the screen, ready to answer the call and yell at whoever was calling at 3am.

Bzzt

Except, it wasn't her phone. The buzzing was coming from her bedside table.

"Shit."

With dread pooling in her gut, Marinette slowly opened the drawer, momentarily blinded from the glowing screen.

That same blank caller screen. No name, no number, only 'accept'.

How did this phone get in here? She had left it in Adrien's room.

Knowing she'd get no answers unless she answered the call, she accepted her fate, and hit the button.

For a moment, she just listened, waiting to see if they gave themselves away. When she just heard trembling breathing, she asked, "who is this?"

"My eyes…"

"Look, I don't know how you got into my home, but this prank isn't funny. It never was."

"My eyes…my eyes…I can't see…"

"Knock it off! And stop calling this phone!"

"You don't believe me. You'd never believe me. You wouldn't believe me then either!"

"What are you talking about? Who are you?"

"Oh how quickly I'm forgotten."

The call ended.

T'ain't no sin to take off your skin

And dance around your bones

I would recommend reading this story on Ao3. I have illustrations and a linked playlist to all the songs used!