AN: I was in a fic exchange thingy for Harry Potter, and this is my challenge: a story where Lupin is deaged and Sirius has to take care of him. It was a struggle for me to think of anything to write, so I apologize if this feels forced. It was fun to make myself write outside my comfort zone, and I hope you enjoy this. It will have several parts and I have no idea how many so please be patient.

Warning: Corporal punishment in later chapters. (Sorry, this was the challenge so I had to write it)

Disclaimer: I own nothing here.

--

"What happened?" Sirius demanded, not believing the sight in front of him.

"He drank an altered potion," Dumbledore repeated what he had just told Sirius. "He went to take his monthly potion, and he must have taken the wrong one, and then happened."

Sirius stared down at the boy, not believing what he was seeing. It was like when someone showed him their childhood picture and you could see the strong resemblance to the child they had once been, but still they were different. It looked like he was seeing a picture of Lupin as a six-year-old, but it was not a picture – Lupin was standing in front of him as a six-year-old.

"It changed him to a child!" Sirius exploded. "Look at him – he doesn't reach my shoulder. He barely reaches my elbow – change him back."

"I'm afraid that is posing a bit of problem," Dumbledore shook his head. "The potion was quite complicated, and it – well, Severus?"

Snape stood to the side, his eyes shining with evil glee at seeing Lupin regressed to child again. "It was a rather unusual potion that I was experimenting with. Something to give the elderly to make them younger. So unfortunate it got mixed up with the real Wolfsbane potion."

"No," a voice squeaked.

Sirius jumped before he realized that it was Lupin talking, his voice high and unbroken, just like a six-year-old.

"That was the only potion there," Lupin insisted.

"Was it?" Snape lifted his eyebrows. "How very clumsy of me, putting out the wrong one."

"He did it deliberately," Sirius bellowed, ready to attack Snape.

"Gentlemen," Dumbledore said sharply. "There will be no fighting in my office. Despite the mixed-up potion – and we will be having a conversation about this later, Severus – we must concentrate on changing Remus back to his former age. Severus, what potion will fix this?"

"It's a complex antidote," Snape admitted in a much less snide tone. "It will take about a week to brew and – and I need the purple Militon berries to start the potion."

"But those only grow on the French Alps, in the summer," Lupin piped up. "That's three months from now."

Dumbledore blinked, but Lupin protested, "That's right – I paid attention in Herbology while everyone else was playing around."

"Summer?" Sirius blurted out. "We can't wait that long. I want him back in his mid-thirties by tonight."

"Well, if you want it, I guess I'll just have to go get it right now," Snape sneered. "I don't have any of the berries – you'll have to wait."

"All right, all right," Dumbledore put his hands up. "Everyone settle down. We're going to approach this thing logically and like adults. You three, take a seat in front of my desk, Lupin in the middle."

Sirius sat down, giving Snape a murderous look, and Snape returned the glare as he sat down, twitching his black robes straight. It took Lupin a little longer to get up into his chair. It was rather high; most first years had trouble sitting with their feet touching the floor. But Lupin tried to climb up and kept slipping on the smooth leather. Snape was smirking, but Sirius reached over and picked the boy up.

Lupin gave a startled cry when he was plucked up, but Sirius sat him down in the chair quickly, leaving his short legs to hang in the air. Dumbledore saw Sirius's help, but did not comment on it.

"Very well," Dumbledore looked straight at Lupin, "tell me what you remember, Remus."

"I came here to see Harry," Lupin's high voice filled the air. "And I knew Sirius would be here, too, so I'd see him. There is still two days until the full moon, and I went by his office," he pointed at Snape, "to see if he had Wolfsbane potion, and he said to come back. I went to see Harry and then I came back and took the potion that was out on the table and then I felt really sick."

Sirius wanted to jump up and rip out Snape's throat, but he forced himself to stay still and listen to his friend.

"I was going to call Snape, but then I got dizzy. I woke up on the floor, and my clothes were too big."

Sirius suddenly realized Lupin was wearing smaller clothes.

"I shrunk them," Snape muttered, "before I brought him here."

"So, you remember everything that happened before you changed?" Dumbledore prodded.

Lupin hesitated, his big eyes blinking, his serious look almost comical on his tiny face, and then said, "Yes, I remember everything. But I fell weird and different now."

"How?" Sirius demanded.

"Everything's so big," Lupin looked around the room, taking it all in. "And you're big too, Sirius. And Dumbledore and everything. And my hands seem small."

"Of course, you're idiot," Snape snarled. "You're six now, not thirty-six."

"I was barely thirty-five," Lupin shot back at him. "And I know what you're doing, Snape."

Lupin's childish voice had trouble with the potion master's name, almost pronouncing it Thnape. That made Sirius so angry he could barely keep still.

"You're a child – you don't know anything," Snape said scornfully.

"I don't work here anymore," Lupin declared. "I don't have to set a good example for the children – let's take this outside!"

"I could carry you out with one hand," Snape jeered.

"No one will be fighting," Dumbledore said sternly. "Severus will be making the potion as soon as the ingredients are available. Until then, we must decide what's to be done with Remus."

"Nothing's going to be done with me," Lupin piped up, pushing himself up straight in his chair. "I'll go home and wait for the potion. I'll be fine."

Dumbledore gave him a sympathetic look but said slowly, "I'm afraid that might pose some difficulty. You may have your adult mind, but you are a bit small to be on your own. We don't want you to get hurt at home, unable to get help. No, no, I think you would be much better off staying with someone."

"You want me to stay here?" Lupin suggested, not quite eager but open to the idea. "I could stay until summer. I can read and talk to students and help with classes–"

"And get in everyone's way," Snape interrupted.

Dumbledore looked calmly at Snape. "Are you offering to take him?"

Snape's eyes widened the smallest bit, and he stammered, "No, Headmaster, I was only pointing out the difficulties with him staying here. The other children are bigger. He'll be run over in the hallways. And what if he accidentally locks himself in a cupboard or falls out the window?"

"I'm not that stupid," Lupin protested, but Dumbledore was looking at Sirius.

"Me?" Sirius blurted out. "I – but, I'm not even supposed to be here. I'm on the run, sort of."

"He should be in prison," Snape told Dumbledore urgently.

"That's not true, Snape," Lupin insisted. "He was innocent, and you know it."

"That is a moot point now," Dumbledore cut through the bickering. "Sirius, you're going to take Lupin, and that's the end of it."

"Where are we going to live?" Sirius demanded.

Lupin blinked at the suddenly question, his fact falling slightly. Sirius wondered if Lupin actually wanted to stay with him for a while (they had been best friends for the longest time), but they had not seen each other all the years Sirius was in prison, and things had changed.

"I know of a house you can use," Dumbledore stated. "Severus, please take Lupin outside while I talk to Sirius."

"I can't stay?" Lupin began, but Snape clamped a hand on his shoulder.

"Let's go," Snape ordered.

"Let go of me," Lupin demanded as he was hauled to door. "I can walk by myself."

Sirius wanted to protest, but they were out into the next room, closing the door before he could object.

"You have to deal with him," Sirius told Dumbledore. "That bastard will stop at nothing, nothing! He could have killed Lupin."

"I see we never grow out of playing harmful practical jokes," Dumbledore said quietly.

Sirius flushed, but insisted, "That was different. Snape did this deliberately. He should pay for this."

"Oh, he will," Dumbledore nodded. "You and Lupin will be staying at his home, Spinner's End."

--

As far as Sirius could see, the only good to come out of the whole debacle was Snape's fury over having to lend his own house to them. Snape bellowed that he would not, and Dumbledore took Snape into the office, leaving Sirius and Lupin out in the hall.

"I can't believe we'll live at Snape's house," Lupim smiled. He looked up at Sirius, up, up, up at the tall man. "You think Snape is a greasy slob like he was back when we went to school and his house is a mess?"

"Probably," Sirius grinned. "We'll have to clean the whole house out when we get there."

A few minutes later, Dumbledore came out. "I will arrange for a floo to take you there."

"Is the nasty git not coming out?" Sirius sneered.

"Don't say that front of the child," Dumbledore admonished before he could catch himself. "I mean, I'm sorry, Remus, I keep forgetting you are not really as young as you look. Which reminds me, we need to get you the appropriate things you'll need."

"Like my books?" Lupin looked up at the even taller wizard. "And my research and my drawings?"

"Those too," Dumbledore smiled.

"All right," Lupin nodded. Then he started off down the hall.

"Where are you going?" Sirius demanded.

Lupin paused, turning back to face them. "I was going to tell Harry and his friends goodbye."

"I think you better stay here," Dumbledore cautioned. "We – uh, might need your help."

"All right," Lupin agreed. He trotted with short steps back to the two men.

"We're going to need some trunks," Dumbledore began.

"I'll get them," Lupin broke into a run.

"Remus Lupin, come back," Dumbledore ordered.

Lupin looked shocked, and as he returned, he said, "You said you wanted my help. I was going to help."

"Stay here," Dumbledore told him, all smiles gone. He went back into the office, leaving both of them out in the hall.

Sirius had a crazy urge to clamp a hand on the child before he took off again, and he struggled to remind himself that Lupin might look like a child, but he was really an adult. He just seemed so small – Sirius knew he could scoop him up with one hand if he really wanted to and carry him around under one arm.

Dumbledore opened the door, looking stern, but the office was empty, Snape having left by floo powder.

"Severus has gone to his house, and he has half an hour to get it ready for you," Dumbledore said as he led them back into his office. "I offer you a seat until then.
Perhaps some tea?"

Sirius opened his mouth to agree to tea, but Lupin was eying the bowl of candy on Dumbledore's desk.

"Would you care for a lemon drop?" Dumbledore held out the candy dish.

As Lupin reached his hand out, Dumbledore warned, "Just two – no more."

Lupin froze, staring at him, but the headmaster was looking at Sirius.

"You'll thank me later," Dumbledore told him. "Too much sugar, you know."

Lupin scowled, but the moment he popped the candy in his mouth, he smiled.

"It's better than I remember. And bigger – when did they start making candy so big? It's fills up my whole mouth. Thank you."

"You're most welcomed," Dumbledore replied, but he looked very serious. "I think you and Sirius are going to have a long period of adjustment."

"What do you mean?" Sirius shrugged impatiently. "We lived together in a dorm room for seven years. A house won't be that much different."

"We'll just have to wait and see," Dumbledore murmured as he stood to go ask a house elf for tea.

Sirius looked down at the small boy beside him who was still sucking on his candy as if it were the best thing that he had ever tasted. Perhaps the headmaster had a point.