Severus Snape awoke with a stabbing pain in his stomach. Groaning he climbed out of bed and went for the medicine cabinet in his bathroom. After moving vials and searching Snape pulled out a vial of green liquid, uncorked it and tossed it back.
The pain in his stomach began to numb and Snape went back to bed. After lying in bed wide awake for a few minutes, he realized that there was no going back to sleep and got out of bed and dressed.
After a cup of tea, he headed out the door to go for a walk in the cool morning air. After walking a few blocks he saw a crumpled figure crawl toward the street and collapse, yelling for help as his face hit the sidewalk.
Snape rushed forward, and checked the boy for a pulse. Relieved to find one, he carefully turned the boy onto his back and was shocked to see Harry Potter beaten and bloody on the ground in front of him.
He gathered the boy in his arms and apparated him to the only place he could think to go.
Snape stumbled as he landed outside the front door to his home, Spinner's End. He knew the boy had no desire to go back to Hogwarts, and this was the only place that Snape could take him.
After wrestling the door open and taking the boy inside, he made his way to one of the bedrooms and laid him on the bed. After banishing the boy's clothes to the laundry hamper, he began to look over the boy's injuries.
A few minutes later, after surveying Harry's injuries, he covered the boy with a blanket and went down to his lab to brew some more potions. Healing potions, bone mending potions, blood replenishers, bruise salves, and more. He had at least five cauldrons going at once.
A couple of hours later, he had more than a dozen vials and pots of salve and headed back upstairs.
Mercifully, for the boy, he was still passed out when Snape got back to him. Looking at Harry lying there so helpless tugged at his heart. He quickly pushed that away and began working with the injuries on the outside, rubbing healing salves into the cuts and scratches all over the boy's body, and bruise salves into most of Harry's skin where he'd been kicked and stomped.
The tingle of the magic along with the pressure from Snape's hands caused the boy to begin to stir.
"Drink this," Snape said, uncorking a vial, holding it to Harry's mouth.
Instinctively, the boy knocked the vial away from his mouth.
"Idiot!" Snape roared. "It's a healing draught, for your internal injuries."
"How did I get internal injuries in the first place?" Harry demanded. "What did you do to me? And how did you get me here?"
Good lord, the boy has no memory of that morning. Snape shook his head. "Mr. Potter, I assure you, I did nothing to cause you harm. I was merely taking a walk this morning when I saw you crawling out of an alley and landing on your face. I brought you back to my home, because I assumed you'd prefer not to be taken back to Hogwarts or to St. Mungo's and you obviously needed medical treatment."
As much as the boy annoyed him, Snape knew that the last place he would want to wake up was St. Mungo's Hospital, where he had watched more than one of his friends die.
Harry seemed to stop and think for a moment before muttering, "Sorry."
Something in that meek little voice tugged at Snape's heart yet again, but he ignored it and reached for another healing draught, this time uncorking it and handing it to Harry. "I trust you can drink this on your own?" he remarked snidely.
"Yes, professor," Harry said dutifully.
"If you're going to be staying in my home, the least you can do is call me Severus," he told Harry.
"If I have to call you Severus, then you have to call me Harry."
"Fine, Harry."
"Fine, Severus."