Severus will be a little OOC in this story because I believe the reason he became so bitter was after years of bullying, the loss of Lily and other factors along the way. Severus is twelve and will act how I believe a twelve-year-old Severus would act. Character ages will be based on Pottermore.
Harry couldn't believe how different Severus' house was from what he was used to. Here the dishes washed themselves, the food was different and the pictures on the wall moved and some even talked. It nearly scared the life out of Harry when a painting in the hallway yelled at him to tuck in his shirt. Severus and Harry were sitting in the living room, Severus was working on an essay and Harry was flipping through one of Severus' textbook.
Harry was amazed by Severus' potions books; he had bought extra books, outside the required book list for first-year. He said Harry could borrow them throughout the school year. Harry was in the middle of a chapter about poison neutralising ingredients when the fireplace roared alive with a green flame. Harry let out a loud cry and quickly backed behind a nearby couch when a bearded figure emerged from the fireplace.
Up until then, Harry had never seen someone walk out of a fireplace and once the initial fear wore off and logic settled in, Harry felt quite stupid for his initial reaction.
"You must be Harry Potter," the bearded figure said, his eye twinkled with amusement as he watched Harry carefully analyse him to figure out whether or not he was friendly or not. "I am Professor Albus Dumbledore, headmaster of Hogwarts. I'm sure you'll be excited to be joining us in a few days. Severus, my boy! How are you doing? Still studying up on potions; I see a bright future for you."
Harry made his way back to the couch where he was sitting and placed a bookmark in the book he was reading because he had a feeling this conversation was going to take a while. Severus had gone upstairs to get his mum while Harry watched Dumbledore tuck his long white beard into his belt. Harry still couldn't believe that a beard could be that long; it was all he could do to keep himself from gaping.
"How are you settling in, Mr Potter? I have spoken to the department of accidental magic and they are in the process of enrolling you into Hogwarts. I just need to work out a few things with Mrs Snape when she joins us-"
"You won't be waiting much longer, I'm here," Severus' mum said, as she and Severus came back into the room. She had four cups of tea in her hand and a small plate of cookies.
"I'm sorry to interrupt you at home but a matter like this had to be tended to immediately. You said if necessary you would take young Harry Potter into your care and I just wanted to make sure that offer still stands. He will be needing a magical and full-time guardian and considering his parents are too young to do it..."
"Of course the offer still stands. I would love to have Harry in my care; I will treat him like my very own son. Severus has already stated that he has reason to believe Harry has been mistreated in his former home and I'm inclined to agree with him considering how thin and frail the child looks for eleven. I will have it no other way," Severus' mother said, sounded quite confident in her decision. Harry felt tears well in his eyes; this was the first time he heard someone saying that they wanted him. It took all of his efforts not to grin like an idiot but it was so nice to feel wanted for once in his life and not just like a burden.
"Well, now that that is sorted, I've come to hand-deliver Harry's Hogwarts letter. The school will supply you with the funding to pick up his supplies. Harry, do you at least have your wand with you?" Dumbledore said glancing over at Harry who was sipping his tea.
"Yes, it's in my pocket; Hagrid told me it should never leave my person," Harry said, bringing his wand out of his jeans pocket for the older man to see. Dumbledore nodded and smiled widely, his eyes twinkling madly. Harry found himself wondering what the man was scheming. He knew the man was nice but Harry could already tell this man was a schemer.
"We'll have to teach you how to store your wand safely, it could snap inside your pocket if you're not careful," Dumbledore told Harry. "You'll come to Hogwarts on September first with Severus; I've already taken care of the paperwork. All you have to do is show up and learn."
"Thank you, sir," Harry said to Dumbledore, smiling. "Are you sure there is truly no way back to my time?"
"I'm afraid there isn't. Travel to the future was strictly outlawed. Any attempts now could be far too dangerous, I'm truly sorry. But, Mr Potter, you must learn that things happen for a reason and sometimes you need to let them play out to truly understand those reasons. Perhaps, it is your destiny to be here," Dumbledore said, standing up and patting Harry on the head. He turned and looked at Severus' mother.
"I'll have the funds for Harry's supplies applied to your account," Dumbledore said. When Severus' mum started to protest, Dumbledore simply raised his hand and shook his head. "That is everything, now I need to go back to the school; the first day is coming up and I have a lot to do."
Dumbledore walked back to the fireplace and Harry watched with wide eyes as the man walked into the flames. When he dropped a handful of powder into the flames and shouted something, the flames turned green and seemed to swallow him whole. Harry stood up and made his way over to the fireplace, trying to figure out where Dumbledore had disappeared to.
"That's floo powder; we can travel from fireplace to fireplace using it. He's fine, don't worry. It's the easiest method of transportation next to apparition and portkey," Severus explained, only receiving a blank look from Harry who had no idea what 'apparition' or 'portkey' even meant.
"What did your relatives tell you about magic? It will help us figure out what you know and what you don't know," Severus' mother asked kindly.
"They always said, 'magic doesn't exist; now don't ask questions,'" Harry said with a frown. His relatives had known all along magic existed and the fact that the word alone made them so angry should have told Harry that something was off. Severus and his mother shared a sad glance.
"I know his aunt, she's a real piece of work and that sounds like something that would come out of her mouth," Severus told his mother.
Harry spent the next hour telling the Snapes about the past ten years with the Dursleys. He left out the stuff about the beatings and being forced to sleep in a cupboard. He simply told him the cruel words they said and some of the chores he'd been expected to do. But Harry could tell by the way Severus looked at him, that he knew there was more. Harry was very thankful Severus had decided not to push for more information.
Severus was now watching Harry as though the boy was about to fall apart, wondering how bad the truth really was. "Don't worry, you're safe now and we will never call you a freak here."
"I'm going to put an owl order in for nutrient potions for you. We're going to need to bring up your vitamin levels and your weight. You might have to keep taking them once you get to Hogwarts," Severus' mother said, writing something down on a bit of parchment. "Why don't you go get ready for bed? You can borrow some clothes from Severus until we can get you some clothes of your own."
The next morning when Harry woke up, it took him several minutes to remember where and when he was. It was still weird to think about a time when he wasn't technically born as the 'present'. Harry got up and put on some of the clothes Severus had given him to wear.
Harry made his way downstairs only Severus' mother working in the kitchen. She was waving her wand as the food seemed to prepare itself. Harry found himself completely amazed by this and spent a few seconds watching. Simply seeing magic in use was an amazing experience for Harry and he couldn't help but think about how much his aunt and uncle would freak out if they saw this display.
"Ah, you're awake! We're going to go to Diagon Alley today. Do you have anything specific you want for breakfast?" Harry wasn't sure how to react to the question. Nobody had ever asked him what he wanted to eat. It was usually his relative telling him what they wanted to eat, not the other way around. Harry wasn't even sure what he wanted to eat because he'd never really thought about what he liked before.
"I think I'll just have some toast and eggs," Harry said, picking out things that were already prepared so he wouldn't feel like a burden.
"Sit down and I'll prepare your plate," Severus' mother told Harry. Harry sat down at the table and watched as the table seemed to be setting itself.
After a few minutes of watching Severus' mother work several brilliant spells, she came to the table holding a plate with bacon, eggs, toast and sausage. Harry smiled brightly and thanked her; Harry had never been given so much food to eat. He was halfway through the plate when Severus made his way into the kitchen and a few seconds later was presented with a loaded plate.
When they were almost finished their breakfast, an owl fluttered into the dining room, carrying a large package. Harry actually found it remarkable that the owl was able to carry such a large package.
"That's for you, Harry. It's your nutrient potions."
Harry took the package from the bird who took a piece of bacon off Severus' plate and flew quickly out the window.
Inside the package was ten individual doses of brown liquid hopefully tasted far better than they looked.
"You should probably pinch your nose when you take those," Severus told Harry who was slowly preparing himself to take the potion. Taking a deep breath, Harry plugged his nose and sent the whole dose down his throat without any of it touching his tongue. Unfortunately, he could taste it in his throat and it was horrible.
"That was nasty!" Harry said, causing Severus to chuckle slightly.
"At least the ones you have are only once a day. I had to take some after a really bad bout of the flu and it was three times a day for five days," Severus told Harry who flinched at the idea of taking that potion more than once within a day.
"Alright boys, get ready; we're leaving in five minutes!"
Harry and Severus went upstairs and cleaned up quickly before going downstairs to leave for Diagon Alley. Severus' mother was waiting but the fireplace for them with a pouch filled with a powder identical to what Dumbledore had used last night.
"We're going to floo?" Harry asked, nervously. Despite having seen Dumbledore do it last night, his mind was still having trouble with the idea of stepping into a live fireplace. It must have been obvious that he was nervous because Severus smiled and patted Harry on the back. After explaining how the floo network worked, Severus stepped into the fireplace and demonstrated the process.
"Make sure you speak very clearly," Severus' mother told Harry once her son was gone. Harry nodded and took a hesitant step towards the fireplace. He stepped into the fire and threw the powder into the flames and cried out, "Diagon Alley!"
It felt as though the world had disappeared from under his feet and that everything was spinning until suddenly, he was back on solid ground and down on his butt. Harry looked around, to find himself in a room with several fireplaces and a door that clearly lead outside. Severus was waiting by the door and somehow wasn't covered in as much soot and dirt as Harry.
Severus smirked at Harry and signalled for him to wait by the door for his mother.
"Welcome back to Diagon Alley, Harry!"