A/N: not following the horcrux story line. But I think you already got the impression that this story is somewhat AU, right?
"Sevvy, can you run to the infirmary and get some more bandages for me, sweetie?"
He nodded and ran off.
When he came back, he took a moment to take in the sight.
The Great Hall had been emptied of tables and benches. Instead, there were now rows and rows of bunk beds. The staff table had remained, but was now filled with every kind of potions, bandages and other equipment the nurse thought she might need. St. Mungo's was standing by as well, but they expected the majority of wounded from the Order to come here.
He shivered when he looked at the pile of clean white sheets, stuffed away in a corner, to cover up the dead that would undoubtedly arrive. Despite the nurse's competence, they did not expect to be able to save everyone.
He brought his supplies to the nurse, who was inspecting her potions supply with a frown.
"What is wrong?" he asked.
"Bill didn't have much time to brew," the nurse replied absentmindedly, "and the school of course, doesn't have enough healing potions in stock for such huge battles. We will have to be careful with our supplies."
He looked at the rows of vials. There was no way it would ever be enough, he realized. People would die without them. Oh, this was so hard…but Daddy and Harry had always said that sometimes you have to do things you don't like.
"I'll brew," he said softly.
The nurse looked at him. His aversion to Potions was well known – and well debated – among the staff.
"Honey, that is very sweet, but are you sure?"
He nodded. "I can do it, Madam Pomfrey. They're not that hard to brew."
She gently stroked his head. "I know you are very capable, Sevvy, but I'm afraid it will cause you stress."
Yeah, and letting her try and heal the wounded when running out of potions wasn't stressful? He shook his head.
"I can brew," he repeated, "I'll start now, so you'll have fresh batches before these run out. Can I set up cauldrons here? I…I don't want to be alone in the dungeons…"
He hoped she wouldn't think him weak, but he really didn't want to be alone, certainly not far away in the dungeons, when Daddy or Harry could come here wounded…or worse…
The nurse nodded, and called one of the fourty house elves that had enough skill to help out.
"Could you please go to the dungeons and bring up whatever Severus needs? And help him set up in a more or less quiet corner?"
Soon he was preparing ingredients. Despite not having brewn anything in a year, his fingers easily remembered their old skill, and he had three cauldrons of healing potion bubbling in no time. Two others had blood-replenishing potion, and a sixth cauldron was simmering as well, with a gooey blue substance in it.
"What is that?" the nurse asked, when she walked by to see how her little potions master was doing.
"It's very old," he said, using both hands to stir different cauldrons simultaneously – and with different stirring patterns, "I found it in mother's old books. It is a sort of antidote against a variety of Dark curses. If you can see where the curse hit, you rub it on. Otherwise, you water it down, one part goo, two parts water, and let them drink it."
"Won't it clash with other potions?" the nurse asked, stunned.
"It used to," he said, "but I figured out that a bit of peppermint takes care of most reactions. And makes it taste better."
She smiled. "You never used to care about the taste of potions," she couldn't hold back the remark.
He stirred again. "I didn't care about much when I was grown-up, did I?"
Despite being very busy, she walked behind him to ruffle his hair and press a kiss on it.
"Just remember we love you very much," she said before leaving in a hurry.
He had to call a house elf three more times to get him potion vials from the dungeons. While he was bottling up the goo, a lot of commotion and the familiar light of a portkey heralded the arrival of the first wounded.
He was glad he wasn't near enough to see their wounds. He still had nightmares about Lucius Malfoy, and he didn't want to see all the blood. House elves raced through the Hall constantly, tending to the wounded, picking up the potions the nurse needed. They were going through them at an alarming rate, and he quickly set up more cauldrons.
The Hall slowly filled with wounded in various degrees of severity. To the left, they had housed the ones that were only mildy injured; broken bones, heavily bleeding cuts, some curses. His goo worked wonders there, and many of the less injured were able to return to the battlefield after being treated.
His arms started to really, really ache from stirring, and his fingers were cramped from cutting ingredients.
"SEVERUS!" Madam Pomfrey yelled, "can you brew Skele-gro? They're using some sort of curse that blasts bones into fragments."
He nodded wearily. Molly Weasley walked by as he tried to chop ingredients with shaking fingers.
"Child, you can't brew like this!" she exclaimed.
"Have to," he replied, looking up at her in exhaustion, "heard of that curse. Know a potion…need more ingredients.." he muttered.
Molly called over two house-elves.
"Please, help him," she said, "follow his instructions to gather and prepare ingredients. No one else can brew, but I won't forgive myself if he falls over with fatigue."
"I can manage, Mrs…Mrs Weasley," he had to convince her of that. If his father and brother wouldn't allow him to join the battle, fine, but he would not allow them to take away the only useful thing he COULD do.
"Sit down, drink some juice and have a sandwich," she ordered him sternly, "while Manny and Piry get the ingredients ready. I mean it, Sevvy."
Seeing that the elves were perfectly capable of preparing the basic ingredients from the book, he allowed himself a few moments of rest.
Then he jumped up again and took over the more complicated preparations and actual brewing.
While he brewed, he saw familiar faces come by; Hagrid. Bill. Neville was brought in, still holding Bellatrix Lestrange's severed head in his hands. He turned away from that, it made him sick. But no sign of his father or brother.
Then, suddenly, just as he was done, a rush of magic filled the air. He felt a pain like he never felt before, not even under the Cruciatus curse, and he fell back screaming.
"SEVVY!" he heard the voices of Madam Pomfrey and Molly Weasley as they rushed to his side.
His body was on fire. It was being ripped apart. Every single bit hurt. Hurt. HURT!
He convulsed, trying to get away from the pain, dimly aware of hands trying to restrain him.
Then everything went black.
sssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss
Bloodsmeared, completely covered in filth, Dumbledore Portkeyed into the Great Hall half an hour later, carrying the limp form of Harry Potter in his arms.
"Poppy!"
"Albus! Thank Merlin…Oh no, Harry…Follow me, quickly."
The old man was surprised when he was rapidly led through the corridors to the actual infirmary.
"Lay him down on that bed, Albus."
The headmaster obeyed. Poppy started casting diagnostic charms on Harry. It was then that Dumbledore saw the occupant of the other bed.
"Sevvy! What happened, why is he here, what…"
The nurse looked up, and pulled him aside.
"Come, Albus. Harry is suffering from magical and physical exhaustion. An elf will clean him up and treat the minor injuries he has. He will remain asleep for quite some time, I am sure, but he will mend."
Dumbledore nodded, a bit relieved.
"Sevvy?" he asked then.
The nurse picked up the small boy and placed him in Dumbledore's arms, then directed him to a comfortable chair.
"Severus is growing up again, Albus," she said softly, "the curse has dissipated. It will be a few days, but his body is already beginning to shift back into its adult form. I've given him Dreamless Sleep because he would undoubtedly be in much pain were he awake."
Dumbledore rocked the limp body.
"Of course," he whispered, "we never realized…Harry defeated Tom," he said.
The nurse's eyes brightened. "He did? He is gone? For good?"
"Yes, he is," Dumbledore said, smiling at the bed, "although I will be having a very long talk with that young man once he is well again about going after Dark Lords without any help at all."
Then he looked a the still form in his arms.
"We never realized that the curse might dissipate once Tom was defeated," he said remorsefully.
"A lot of lives would have been lost without him today," Pomfrey said, stroking the dark hair, "he brewed like crazy. You know how much he hates it, but he did. We'd have lost many more if it weren't for him. All we can do now is wait, Albus. They will both remain here, and you can stay with them if you promise to go clean up, have something to eat and then go to sleep in the spare bed."
Dumbledore shook his head.
"Enlarge Sevvy's bed. I'm staying with him, I don't want him to be in pain if the potion wears off early."
Quickly floo'ing to the Hall to make sure everything was under control, the nurse did a final check-up on Harry.
When Dumbledore returned, he was subjected to her wand as well, and directed to the bed he would share with his son.
"What happened, Albus?" the nurse asked, "Sevvy started convulsing suddenly about an hour ago. Was that the moment Harry killed You-Know-Who?"
Dumbledore nodded, and arranged his son more comfortably in his arms.
"Yes, it was. The battle took quite some time. When we arrived at Godric's Hollow, all was still quiet…"
A/N HA!