Severus Snape—thirty years old, freelance potioneer, researcher, all-around bastard—is content with his status quo. The majority of his week is spent in solitude and his weekends consist of meals with a rotating roster of friends—both old and new—and he’s proud of the balance he has managed to strike, the careful weighing of scales so that he’s never over-tired from the presence of others or so reclusive that he’s considered a hermit. Holidays get a bit crowded but, altogether, Severus is leading his ideal life.

Severus is happy.

And then, on an average Wednesday, his Floo flares to life and Lily Potter née Evans stumbles into his house. Her face is bright red, her movements frenzied, and her voice is panicked when she calls, “Sev!”

“Lily?” asks Severus from his potions room, immediately dousing the fire under the cauldron in front of him before racing into the living room. Lily is leaning against the fireplace, panting. Her right arm clutches the shoulder of her son, Harry Potter, who Severus has not seen since Christmas—which had suited him very well. He’d never known what to do around the little boy who looked so similar to James Potter but acted just like a tiny Lily. Severus inches closer. “What happened?”

“James…and Sirius…in the hospital,” Lily gasps. “Can’t bring…Harry! Look after him!” And then she all but shoves Harry at him and he has to catch the boy by the shoulders so that he doesn’t trip and fall. Before Severus can open his mouth and demand a more in-depth explanation, Lily has already dived back into the Floo, calling, “St. Mungo’s Visitor Center!”

Severus stares at his fireplace, then down at Harry. “Oh Merlin,” he murmurs. “I can’t take care of a baby.” He’d only held Harry once after the boy had been born, and he’d nearly dropped the boy. Lily had smiled at him and then instructed him to never pick up her son again, a sentiment James had echoed much more hotly.

“I’m ten,” Harry says, thoroughly unimpressed. Then, “Mum said you’d play with me. She was lying, wasn’t she?”

“Don’t talk about your mother like that,” Severus snaps.

“I didn’t say anything bad about her!” Harry responds. “Just that she was stressed. I’m stressed. Mum didn’t want me to know but I’m pretty sure Dad’s in a…a…a coma?” He leans closer. “Tell me what a coma is.”

“Your mother would be upset with me.”

“Mum doesn’t have to know. I’ll pretend everything’s all right.”

At that moment, Severus is absolutely certain that Harry James Potter will end up in Slytherin. Merlin help the poor teachers that will have to deal with him. He finally lets go of Harry’s shoulders and says, “Go sit down. I’ll turn the telly on and you will be silent and we will get along swimmingly.”

“Is Doctor Who on?”

Severus, who hasn’t turned on his ancient television in a year but desperately doesn’t want to deal with him, says, “Yes.”

Harry scowls at him. “You’re lying.” Then, louder, “I don’t want to watch the telly!”

Severus glares down at him. He’d never been left alone with Harry before—there had always been a buffer between the two of them, whether it was Harry’s parents or Harry’s friends. Now the two of them are left to deal with each other’s personalities and it is not going well. He says to Harry, “Well, I don’t have toys so your only other option is to sit still and do nothing.”

“Do you really not have board games?” Harry complains. “I knew you were boring but I didn’t realize you were this boring.”

That sounds exactly like something Draco Malfoy would say and the thought has him reeling. He cannot allow the two boys to meet—it would be the end of him. He asks, “Why would I have board games?”

“Because they’re fun.”

“I think potions are fun.”

Harry stares up at him for a moment before a blinding grin overtakes his face. “I think potions are fun, too! I can help!”

“Absolutely not,” says Severus. “You are a child. You cannot possibly expect me to—”

“If I don’t help you with potions then I’ll sing nursery rhymes at the top of my lungs.”

“I’ll cast a Silencio,” Severus hisses.

Harry smirks up at him and declares, “I’ll tell Mum.”

Damn brat. Severus grabs him by the elbow and hauls him into his potions laboratory, thankful that he hadn’t been working on anything particularly dangerous. Harry seems too delighted to care about Severus’s rough handling and the boy doesn’t even flinch when Severus hurls a pair of gloves at him. “Put them on!” he barks. “Don’t let me see even a hint of anything past your wrist!”

“Because then you’ll steal my fingers?” Harry guesses.

“What—Harry James Potter, what are you on about?”

“I know some potions use children’s fingers. Like the Immolation Potion.”

“Which, I assure you, I have no intention of ever brewing!” And then, incredulous, “How do you know about that, anyway?”

“It was in Grandpa’s book of notes,” Harry explains.

Severus goes right back to scowling. “Fleamont Potter is a hazard and should not be allowed around children. Honestly, does he not understand the concept of age-appropriate reading materials?”

“I thought it was cool.”

“You would.” Severus reignites the flames under the cauldron, bringing his potion to a simmer. “Don’t touch the cauldron. You will burn yourself.”

“I can handle heat,” says Harry.

“Not this heat.”

Harry rolls his eyes as if Severus isn’t trying to save him from excruciating pain. Severus ignores any further whining from the boy and instead sets him on prepping the yarrow, which is simple enough that even a bumbling idiot can do it. To his surprise, Harry is perfectly competent and performs the given task with ease. He should have known—Harry is Lily’s son.

“Say,” says Harry while Severus is stirring the potion—twenty-three turns counter-clockwise—with intense concentration, “you never did tell me what a coma is.”

“Because I shouldn’t,” snaps Severus. Twelve turns clockwise.

Harry huffs. “I’ll figure it out myself if you don’t tell me. I’ll figure it all out. I’m asking you because this way you can make sure I don’t learn anything bad.”

Severus purses his lips. Adds the yarrow. It’s frustrating, how similar Harry is to Severus himself when he was younger—oh, sure, Harry got his stubbornness from his mother, but Lily had gotten hers from Severus. If he were a young boy put in the same situation, he would be doing the exact same thing Harry is, though perhaps less politely. With a grudging surge of empathy, Severus bites out, “It’s when someone is unconscious for long periods of time, usually due to injury or illness. Sometimes healers induce comas medically if they believe it’s necessary.”

“Do you know which of those Dad has?”

“I don’t,” says Severus, voice clipped. “All I know is what your mother told me when she dropped you off. I never knew about the coma until you mentioned it.”

“Oh,” Harry says quietly. Then, “I can chop the mugwort.”

Severus silently hands him the mugwort. Of course the boy had already figured out what potion Severus is working on.

As the silence continues and Harry contemplates in silence, Severus observes him. If the boy really is going to be a Slytherin then Severus shouldn’t let him think for too long—who knows what sorts of schemes Harry would cook up? Draco already causes Severus enough problems when he visits with Lucius and Narcissa—an unsupervised Harry could be a disaster.

So, Severus says, “He’ll be fine.”

Harry’s head snaps in his direction. “What?”

“Your father,” Severus clarifies. “James Potter has always been…resilient.” Like a cockroach. “He will be fine.”

Harry squints at him and, for a moment, Severus is worried that the boy will disagree and—Merlin forbid—start crying. Instead, Harry smiles at him and says, “Yeah. Dad’ll be fine. I think Padfoot got his hair signed off, though. He’s probably sobbing over it in St. Mungo’s.”

Severus snorts. Black had always been unusually fond of his hair. “Serves him right.”

Harry giggles.

It’s…easier after that. They hit a brief snag when Severus realizes that children require food at regular intervals of time and Harry proves to be remarkably picky about what he puts in his mouth, but they both end up snacking on the rosemary and chamomile in his potions stores and that’s that.

It’s nearly ten in the evening when Lily finally returns to pick up her son. She looks weary and exhausted when he opens the door—this time she actually knocks instead of emerging from his fireplace unannounced—and Severus immediately drags her inside and sits her down. “Drink some tea,” he says firmly, shoving some that he’d already made into her hands.

“Thank you, Severus,” she murmurs. Then, “Where did you put Harry to bed?”

Severus’s brows knit together. “What do you mean?”

“Severus,” Lily says slowly, “his bedtime is eight-thirty.”

“How was I supposed to know?” Severus sniffs. “He’s still awake—he’s in my potions room right now.”

“You left him unattended?” Lily demands, coming to a stand. “That—that could be dangerous!”

Severus waves away her concern. “I made sure that there’s nothing sharp for him to touch and the potion we’re working on is completely safe in all its iterations. Your son is a competent brewer and a tolerable partner.”

Lily stares at him, her mouth opening and closing like she’s a dying fish. Then her lips spread into a grin. “You like him!” she declares.

“I do not,” Severus immediately replies.

Lily just laughs uproariously. “Oh, thanks for that, Sev,” she says when she’s done. “I needed a good laugh. It’s just, the entire day has been awful…”

“Harry mentioned that Potter is in a coma?”

“He is,” says Lily, smile melting off her face. “The healers say he’ll probably wake up within the next two or three days, though, so…”

“That’s good,” says Severus. “I’m sure Potter is perfectly all right. Nothing as simple as major trauma can take him out.” He’s like a cockroach, in that sense—or in many senses.

Lily smiles weakly. “You’re right. Everything will be fine.”

Severus hums. Then, with much difficulty, he inquires, “And what of the mutt?”

Lily laughs at him, delighted by his and Black’s continued rivalry. “His pride took a serious hit but he’s been given a clean bill of health. Currently en route to a salon as we speak.”

“Maybe they’ll realize his hair is a lost cause and chop it all off,” Severus muses. “It would certainly be an improvement.” Not. Black has frustratingly perfect hair and Severus will never forgive him for it. Severus’s hair, no matter how well he takes care of it, always seems limp and greasy.

“Since I love you, I won’t tell him you said that,” Lily says sweetly.

“I could take him.”

“I’m sure.”

Vaguely offended, Severus huffs and says, “I’ll go grab your brat of a son—”

“Oh, you do like him!”

Severus doesn’t deign that worthy of a response. Instead, he stomps back into his potions room, where Harry’s full attention is on bringing the cauldron in front of him to a rolling boil. Severus says, “Your mother—”

“Shh!” Harry shushes. “It’s almost lavender—”

“Harry, you really must—”

“Oh, no, it’s turning green. Why is it turning green?”

Severus blinks before leaning over and checking the cauldron. He says, “Did you add in the yarrow at the correct moment?”

“I’m not stupid—”

“Everyone your age is stupid—”

“Rude!”

“I know. You put in the yarrow at the wrong time.”

“No, I did it exactly three minutes after I finished stirring!”

Harry and Severus proceed to bicker viciously over the minutiae of the potion brewing for several minutes before Severus feels a prick at the edge of his vision. When he looks over, Lily is watching on with a fond expression. Inexplicably embarrassed, Severus demands, “What?”

“I think I’ll use you as a babysitter more often.”

Before Severus can deny her, Harry says, “Nice.”

“Also,” says Lily, “Harry, which way did you stir the potion?”

“Clockwise.”

Severus closes his eyes. “You’re supposed to stir counter-clockwise.”

“…Whoops.”

The sage green concoction chooses that moment to explode, coating the three of them in sticky mush. Severus watches the mess in his lab with horror while Lily and Harry giggle madly. …Surprisingly, he’s still not too opposed to babysitting again. Sometimes. With a lot of cooldown time in between. Like once a month, maybe.

As Severus sets Harry on scrubbing down his table, he can’t help but smile.