This was just a fact.

Fire is hot, Dementors feed off of happiness, Draco Malfoy has an extensive knowledge on Harry Potter.

Throughout his first seven years at Hogwarts, Draco would unload these facts on his parents, especially during the holidays. (However, if he added a new fact to his repertoire, he would definitely owl home with it.) Thus, Lucius and Narcissa Malfoy had an extensive knowledge on Harry Potter. From how he liked his tea, to what he ate when in a certain mood, to spots in Hogwarts he frequented when he had nightmares, to what precise shade of green his eyes were (and the fact that they seemed to lighten and darken in certain moods. Draco had declared that no artist could fully capture their proper liveliness and brightness; so, of course, Draco had had to give it a shot. He'd taken up art sometime in fourth year, after the success of the "Potter Stinks" badges. He'd picked it up surprisingly fast; he dropped it, though, when he decided that even he couldn't portray Potter's eyes quite right. (He'd picked it up again during sixth year, though, as a sort of coping mechanism. His skills improved drastically.) What had been entertaining for his friends to watch during this time was that Draco had often antagonised Potter just to see a certain shade of green, or to see how the light hit his eyes at specific moments) to how he talked, to his tells when he was lying to how far he went when you insulted his family (Draco knew that one from personal experience; it'd been one of the first owls he'd sent home containing a Potter Fact in first year).

His parents, however, were a candle flame next to a bonfire compared to his closest friends in terms of knowledge about Harry Potter; they'd had to listen to the smallest of facts that Draco picked up on every day for the whole seven years. But oh, Draco wasn't done. They still had eighth year to go, after all.

"He had a nightmare last night," Draco murmured to Pansy at breakfast one Friday morning.

"What, stalking him again?" she asked.

Draco looked scandalised. "Of course not! Just look at him. He's eating french toast, and he's got extra maple syrup on top- must've been a bad nightmare- with only a couple of strawberries. And he's got a cup of coffee, too, to wake him up. If he's got syrup on his toast, it must be three sugars in the coffee, and probably a full shot of espresso."

"And?"

"Alright, maybe I saw him out by the Black Lake last night skipping stones-"

"You were stalking him!"

"Was not!"

"What were you doing, then?"

"I was going to get potions ingredients, as a matter of fact."

"Oh, were you now?"

"I was!-"

"Alright, you two," Blaise interrupted. "It's just Potter."

Under his breath, Draco muttered, "Just Potter, just Saint bloody Potter with his wonderful scar and his-"

"Draco!"

Draco rolled his eyes. "Alright, alright. So, yeah, Potter had a nightmare. Doesn't make him special, though," Draco added. "I had a nightmare too."

"So did nearly everyone who had such a big role during the war. I'd be more surprised if you slept peacefully." Pansy said, taking a bite of her toast. Draco froze, like a deer in headlights. His body stiffened up, eyes wide, and he stopped moving entirely. "Draco. What did you do?"

"Nothing! Absolutely nothing! I slept terribly last night, did I say?" He started moving very exaggeratedly, and speaking loudly and with more bravo. "Up all night collecting ingredients for- but that's not important!" He waved his hand like he was waving away what he'd just said. Pansy and Blaise exchanged a look.

For as long as they could remember, Draco had always tried to hide secrets and cover up lies with big distracting tales and physical things. "I was out in the forest and then down in the old potio- I mean-"

"Darling, you can't hide things. Spit it out."

"Well..." He paused, then deflated, letting his body sag, looking almost ashamed. "You said it yourself," he said, far quieter. "Everyone who had a big role in the war has nightmares now. I- I hate them- the nightmares, I mean- and I'm pretty sure everyone else does, too; Potter was talking about his nightmares earlier. You can tell 'cause he looks over his shoulder like he's looking for- for the Dark- for Voldemort. And he tenses up, and he just looks annoyed. He's definitely tired of the nightmares, now the war is over and all.

"We're all supposed to be happy and smiling and perfectly normal now, but we can't be normal when we're all being plagued every night by reminders of the past. I'm tired of it, but Dreamless Sleep is addictive and temporary.

"So, um, I was trying to make a - a potion that can fix that. I got permission from McGonagall, and I'm using Sev's old classroom and his ingredients, I'm just experimenting..."

"Oh, Draco," Pansy said, her voice a little softer than usual.

Blaise leaned over and patted Draco on the shoulder. "That's good of you, Draco."

"Yeah, we're- well done, Draco. Well done."

That night, Draco snuck down to the potions rooms again.

He set up all the usual wards, letting people in but notifying him and identifying them. Protection wards around the ingredients and the cauldrons and the possible danger zone and himself.

Finally, he set up the small muggle radio in the corner; it'd been here when he'd started making the potions, and McGonagall told him she'd put it there in case he wanted music to work to. She showed him how to make it work manually- but that'd been months ago. Now Draco just cast a few spells at it, and it sprung to life, blaring the newest popular music. Draco had been listening to this specific station for so long, he actually sort of knew a few of the songs. As he grabbed a scalpel to start cutting up ingredients, he sang along quietly to the songs, making sure his silencing charms were up and working. As he poured the first tray of ingredients into the cauldron, bubbling with water mixed with three drops of Essence of Dittany, he felt something brush over his arm. He shrugged it off as the breeze- the window was open- and shut the window quickly. He didn't want anything as unreliable as a breeze to potentially mess up his potions.

When he was on the last step- stir clockwise slowly seven times, and then wave your wand to complete the potion. It should take on a "shimmering violet tint", he decided to add a few Lacewing Flies- because why not? He knew Lacewing Flies were usually used in polyjuice potions, but other items in the potion caused other things like poisoning, inflammation, and death, but instead just sent the imbiber to sleep. An ingredient of polyjuice potion couldn't do much harm, right?

Not really thinking, he didn't step back as the potion started bubbling more violently. When he looked down, it was a navy blue, and matt as anything, although still bubbling. He barely had time to recall that Lacewing Flies were highly reactive when paired with ground-up Dragon's Heartstring and duck before the potion- a rather acidic potion of now near-black goop- exploded. It hit the walls of his containment charms, and went no further, thankfully. A quick "Scourgify!" and it was gone.

He sighed, resigning himself to making another derivative of the Dreamless Sleep Potion when he remembered the train of thought he'd had earlier.

Other items in the potion caused things like poisoning, inflammation, and death, but instead just sent the imbiber to sleep.

Caused things like death.

You can't counter something like that, can you?

But the potion didn't cause any pain or casualty- just sent the drinker to sleep.

Sleep!

That was it!

He jumped up, Accioed his notebook and a nearby quill and ink he hadn't seen lying about (or he would've cleaned it up; it's not very responsible to leave liquids in the same space as a potentially volatile substance, especially when they could mix and make something truly nasty) and scribbled down his train of thought.

DEATH FROM POWDERED ROOT OF ASPHODEL + INFUSION OF WORMWOOD + VALERIAN SPRIGS WEAKENED BY SOMETHING TO MAKE IT NOT PERMANENT

SOMETHING COUNTERS THE PAIN?

SOMETHING COUNTERS THE DEATH IN ITSELF?

TURNS IT INTO SLEEP INSTEAD

And then, so his future self or any other potions masters who may read this in the future to parade his brilliant work didn't get confused, Draco wrote, very slowly,

DREAMLESS SLEEP IS NON-PERMANENT DEATH

With this revelation, he continued with his theory; mainly, going through and listing the ingredients and what they did, and how they were counteracted by other ingredients; or how they combined or reacted with others.

Finally, he reached the very last one.

1 ML UNICORN BLOOD

Just the very slightest bit; what did it even do? What did unicorn blood do? Draco wasn't good with animals. He frowned. Looked around. When his eyes landed on a wriggling vial of- something, a thought came to mind.

He returned to the classroom a few minutes later, tentatively stroking the spine of the Monster Book of Monsters Hagrid had had them buy for his year of teaching Care of Magical creatures. When the beast seemed to have calmed a little, Draco flicked through its pages carefully until he found the passage he was looking for.

"Unicorn blood can be drunk in order to keep a person alive. However, the act of slaying a unicorn will cause the drinker to suffer a cursed life."

That seemed right. But how did it-

OH!

Oh, oh oh, oh, oh!

He grinned. Unicorn blood can be drunk in order to keep a person alive. It counteracted the combination of the Powdered Root of Asphodel combined with the Infusion of Wormwood and Valerian Sprigs- but, as Draco looked back up the list, there was no ingredient that would make the potion addictive as it was. Unless...

"the act of slaying a unicorn will cause the drinker to suffer a cursed life."

Perhaps...

What if instead of causing the drinker of the blood to live half a life, it cursed them in another way? It made them addicted to the potion?

That would mean that the drinker would eventually build up a tolerance, and either have to deal with the nightmares, or use a far stronger form of sleeping potion. The stronger ones were all also ridiculously addictive, so the user would basically become an addict... All because of one ml of unicorn's blood?

Wow.

He decided to test it out. After all, that's what all good potioneers decided to do.

He took two clippings of Mandrake root, still alive and potted. To one of them, he added a few drops from one of his many batches of textbook-perfect Sleeping Potions; the other could wait a little.

He made a new potion- this one without the unicorn blood. Surely it couldn't be that simple to make a non-addictive Sleeping Potion? But then, why hadn't someone else? Didn't everyone get nightmares? Perhaps just not enough to try and alter an entire potion.

He added the potion without the unicorn's blood to the second mandrake clipping, stepping back just in case- you never knew what could happen with potions. He'd learned this lesson many times over from potions gone wrong. When nothing happened, he stepped closer. The first Mandrake root was dead still, flopped over as much as it could; asleep. It'd wake up in a bit, he'd only added a few drops. As he was waiting, he decided to go get some more Mandrake clippings from the Herbology sheds. He'd gotten all his other ingredients from the Forbidden Forest, but Mandrakes didn't grow there. They made excellent test subjects; a little rough, and liable to react badly with some potions ingredients, but as long as you were careful you were fine. They all had the same reactions to things like poison and fatalistic things and sleeping potions as humans did, which was Draco's favourite thing about them. In addition, being only clippings of the full plant, they did not scream or anything terrible like that. They were quiet, waiting to be tested. And if you did accidentally kill one- well, you could powder it or dice it and reuse it in a potion!

He grabbed his notebook and quill before he left the room, planning out everything he was going to do the next day, once the Mandrake roots had had plenty of time to react and wake up.

He stepped out into the cold air; it was dark tonight.

Cloudy, so the moon's light was diluted and the stars were invisible. Perhaps he'd go to bed afterwards, instead of returning to the potions room. He could leave the wards up, and return to work all of tomorrow; he'd done all of his homework but for his Transfiguration essay, and he'd half-arsed that already, it just needed some editing.

If he told McGonagall about his new revelations in Potions, he was sure she would let him off. She was letting him do all this experimenting because she didn't like the victims of the war having nightmares so much, either; if he told her he thought he'd made progress, he was sure she'd understand.

But, yes, it was a chilly night; it made Draco long for his bed, soft and warm. He collected the Mandrake snippings drowsily; didn't really remember making his way down to the potions classroom and storing all the snippings. Next thing he knew, he was crawling into bed and falling asleep, forgetful of the nightmares lurking in the darkness of the night.

He didn't notice, a few minutes later, an invisible figure, hidden from his wards under a cloak, slipping out of the potions classroom having inspected Draco's notebook where he left it after dropping off his Mandrake root clippings.

He wasn't at breakfast the next morning to see Potter looking for him, a "theoretical" question about sleeping potions and draughts of death and fatal potions on the tip of his tongue. (Although Pansy and Blaise were, and shot each other a knowing look and an eye roll.)

Draco was down in his potions room, alert with a Pepperup potion or two and a strong cup of coffee (how the muggles came up with this stuff, he'd never understand, but it was heavenly), sleeves rolled up, Harry Potter the last thing on his mind for once.