Thanks for all of the reviews/favs/follows! And thanks especially to the Guest review that said how cannon this feels to you! I try really hard to make it that way and I'm so glad you think it is! I really wanted to make this story as cannon as possible and so I try not to take any really huge liberties with characters or plot. Thanks so much!

Over the next few weeks they began making the potion for the animagus spell. It involved several trips to Slughorn's personal store room in the middle of the night and after a lot of arguing they decided to use an empty classroom on the seventh floor. By the looks of it no one had been in to clean in quite a while and they came to the conclusion that it was safe.

After that they made several more nightly trips to Slughorn's private store rooms, collecting the different ingredients.

As the days passed they took turns darting away from class to check on the potion. As luck would have it the room went undisturbed. They're only obstacle was Snape trying to follow them. Fortunately it only took two of them at a time to stop him and most of the school just thought this new wave of dueling was just an extension of the old.

Snape for his part was getting more and more aggressive in his questioning.

It culminated when Sirius caught him discussing his suspicions with several other Slytherins in the dungeons. They however did not look convinced. Sirius waited until Snape began to climb the stairs to the Great Hall and jumped in line next to him.

Snape reacted quickly by reaching for his wand. "What do you want Black?" He snarled.

Sirius glared at him. "I thought we told you to leave Remus alone."

Snape's eyes narrowed. "I know he leaves the castle at night. How does he get under the tree?"

Furious Sirius shoved him. "What, did you follow him?!" He yelled.

"It wasn't that hard." Snape said proudly.

He clenched his fists furiously. "I aughta kick your ass."

"Well how's he do it? Does the teacher do it? I see McGonnagall take him there. What happens?" Snape pressed, eyes glittering.

Sirius grit his teeth. "Why don't you go find out?" He snarled. "Just touch the knot on the tree and see what happens."

Snape's eyes went wide. "What happens?!" he asked. "Why's he go there?"

Sirius shrugged, pretending to be ignorant. "I dunno. Why don't you find out?"

Snape looked him up and down, eyes still wide. They had made it to the Great Hall and after a moment He hurried off to his table. Sirius stood for a minute feeling vindictive and felt so until he reached the Gryffondor table. Remus was gone and he realized it was a full moon. Suddenly he no longer felt pleased with himself or even remotely vindictive. All through dinner he kept looking over his shoulder at Snape, making sure he was still in his seat.
Next to him James was talking loudly to Peter about an upcoming Quittich match and payed him no attention.

However, by the time they were halfway through diner he realized Snape was still in his seat, all was well and he began to relax and join the conversation. "Well yeah, Ravenclaw's got a great keeper but we have a fantastic seeker. All he has to do is catch the snitch early. Mind you, I'm still gonna try and score a few. . ." James said

"I dunno, Chandler is pretty fast for his size." Peter said, leaning on his elbows and glancing at the Ravenclaw keeper across the hall. "Match might be over you score one."

"Knock it off, James can get past him." Sirius said, waving his hand. He glanced surreptitiously over his shoulder and froze. Snape was nowhere to be seen. He swallowed hard and glanced at James who was now laughing loudly and telling a story to three other people.

Surely Snape wouldn't go after Remus. If he really thought he was a werewolf he wouldn't be that stupid. Still .. . He glanced around the hall again and felt his heart sink. He hated Snape, that was true, he couldn't stand the guy but Remus could kill him and that was different.

"James," He said in a quiet voice. "James, I think Snape went after Remus."

James looked up, laughter still in his eyes. "What are you talking about?" He grinned.

"James, I told him how to get under the tree."

The laughter vanished quickly and James was left looking stunned. "You did what?"

Sirius shook his head, not sure what to say. "I mean. . . I didn't think. . . I didn't think he'd actually. . . It's a full moon. . ."

James scanned the Slytherins and shot from the table,dashing towards the door. Sirius followed, insides twisting.

Ahead of him James was running full tilt towards the whomping willow looking panic stricken. When he was close enough he whipped out his wand and stunned the tree on the knot and quickly slid down the passage. Sirius had to jump back as the tree started moving again. He skidded back and paused to catch his balance. The minute he was steady he drew his own wand and stunned the tree again.

He was halfway through the passage when he heard a loud yelling sound.

"Get off me!" Someone was yelling.

"Shut the hell up!" He heard James roar. Both of them came tearing past and Sirius was knocked against the wall. Quickly he followed them back out of the passage and onto the grounds. James dragged Snape a good distance away from the tree and threw him to the ground before standing with his hands on his knees, doubled over. He was gasping and panting and his face was white as a sheet.

Sirius came running up but before he could speak James slugged him. He fell back, feeling stunned. "What the-?" He yelled.

"What the hell were you thinking?!" James screamed over him. "He could have been killed!" He tore at his hair and looked around wildly as Sirius got to his feet. "Did you even think about Remus? Did you think about what that would do to him? How he would feel if he hurt someone?"

"He's a werewolf! I knew it!" Snape cried, sounding triumphant.

"Shut up!" James yelled, turning to him. "If you ever tell anyone I'll make you wish you were dead!"

"He's a freak! A dangerous freak!"

"No, you caused the danger! You chose to follow him! God, damn it, Sirius why the hell would you tell him?"

Sirius rubbed at his jaw. "Look, I'm sorry! I wasn't thinking." He said.

James tore at his hair again. "I can't deal with this! You need to stay away from me."

Sirius tried to argue but was cut off. "What on earth are you three doing out here?" Professor McGonagall cried, striding across the grounds. She looked livid and Sirius began to wonder how the situation could get any worse.

James was still winded and tugged at his hair, staring at her with wide eyes. "Professor. . ." He raised a hand as if to speak and her nostrils flared.

"What were you doing in there?" She hissed, anger overpowering her voice.

"Black told me how to get through!" Snape yelled, glaring at Sirius. "What's Dumbledore letting thatthing at Hogwarts for?"

Sirius and James both made a move to lunge at Snape but were stopped by Professor McGonagall shooting sparks up into the air. "That is enough!" She cried. "All of you will follow me to Professor Dumbledore's office. Immediately!"

They followed her back into the castle. Sirius could tell James was close to losing it and kept his mouth shut. Behind them Snape looked both gleeful and stunned at the same time. He wondered who James was more angry with.

McGonagall left them outside Dumbledore's office and they all stood in silence. James was leaned against the wall, eyes closed and body tense. "James?" Sirius asked in a tentative voice.

James opened his eyes. "Don't talk to me."

He swallowed hard. "I'm sorry!"

"I said don't talk to me."

"How long have you two known?" Snape asked. He seemed to be getting over his shock.

"Get bent." Sirius said.

"He could have killed me!" Snape's eyes flickered, looking rather happy about it.. "You could have killed me, Black."

"I could still." Sirius snarled. He wished James would back him up but James was still standing against the wall with his arms crossed and his eyes closed.

"I bet you'll be expelled for this!" Snape looked like someone had told him Christmas was coming early. "Maybe you and the werewolf both."

This time Sirius and James both lunged at him but Snape managed to dance out of their reach. "Shut your mouth." James said in a hoarse voice.

Sirius turned to look at him and was about to speak when James shook his head. "Don't." He said again. "Please don't."

A moment later the door to Dumbledore's office opened and Professor McGonagall ushered them in, looking severe. Dumbledore was sitting behind his desk, hands folded and face grave. Sirius couldn't help but wonder if Snape was right. If he was about to be expelled. His record didn't exactly help him any either. He swallowed hard. Getting expelled was probably next to being a squib to his mother. She'd probably kick him out. He glanced at James and wished his friend would look at him. He regretted shooting his mouth off now. He was sorry and he wished James would see that.

"You three were seen coming out of the passage under the Whomping Willow." Dumbledore said quietly. "Mr. Potter, Mr. Black, I know the two of you are aware of how dangerous that is. I have to ask, did you lead Mr. Snape there?"

"No sir." Said James in a steady voice. "He figured out how to get under the tree and I went to stop him." Sirius felt his heart leap, James was covering for him.

Dumbledore gazed at James for a long moment before turning his attention to Snape. "How did you find out how to get under the tree?"

Snape's eyes glittered. "Black told me only he didn't tell me there was a werewolf on the other end." He glanced at Sirius malevolently.

Dumbledore paused for a moment before looking at Sirius. "Is this true?"

Sirius glanced at James who was glaring at him and nodded. "Yeah."

"May I ask why you did this?"

Sirius felt his mouth go dry. "I didn't think he'd be so stupid." he said, trying not to sound scared. "And I guess I thought if he was, then it'd be his fault." He glanced at Snape, hoping he got the message.

Dumbledore frowned. "That was a very terrible thing to do. And even if you have little regard for Mr. Snape's life, did you consider how this would make your friend, Mr. Lupin feel?"

Sirius wanted to retort but didn't. This wasn't like being chewed out by his parents. He couldn't mouth off to the headmaster and anyway, he was in enough trouble so instead he bit his tongue and shook his head.

"I don't think I need to tell you that Mr. Lupin's enrollment in this school is a very precarious matter. There are many people who would object." Dumbledore turned to Snape. "Therefor I must ask you to refrain from telling anyone about Mr. Lupin's condition." Snape's face fell. "This is a very serious matter and if you insist on telling the other students I may well be forced to expel you. You would be ruining Mr. Lupin's social and academic career."

If it was possible, Snape's expression became even more let down.

"Mr. Potter, I'm very grateful that you were able to set aside your differences with Mr. Snape and come to his aid. Thank you." James just looked at the floor and nodded. "If you'd like, you can return to your common room."

James nodded again and Sirius tried to catch his eye but he refused to look at him. The door shut and James was gone. Sirius stood with his insides twisting.

"Both of you are going to receive detentions for this, however I will leave that up to Professor McGonagall and I'm afraid Mr. Black that I'm going to revoke your Hogsmeade privileges."

Sirius felt his heart sink further. "Are you gonna tell Remus?" He asked.

"He has a right to know."

It was true but he wished it wasn't. "Are you gonna write home?" He asked.

Dumbledore folded his hands. "I think that this matter should remain inside the castle. Minerva as I said, I'm leaving the detentions in your hands."

Professor McGonagall cleared her throat. "Fifty points from both of your houses. Mr. Snape, you will be helping Professor Slughorn in the dungeons and Mr. Black you'll be helping Mr. Filch in anything he asks."

"How long?" Sirius asked before he could stop himself.

Her nostrils flared. "I think at least a month. I am honestly revolted in your flagrant disregard for human life and for your own friend."

Sirius hung his head. He wanted out. He wanted to go find James and fix things.

"Well, I believe that it's probably time for the two of you to get back to your dormitories." Dumbledore said. "Please don't let anything like this happen again. I'm very disappointed tonight."

As soon as he was released Sirius ran straight for Gryffindor Tower. He had to find James and talk to him. Everything was a mess and his best friend was ready to kill him.

When he reached the Gryffindor common room James was nowhere to be seen but fortunately neither were most of the other Gryffindors. It took him a moment to realize that they were probably still at dinner.

He threw himself into an armchair by the fire and sat for a moment, fidgeting restlessly before getting up and pacing.

After a while the Gryffindors began filtering in in twos and threes from dinner, talking happily. He searched each face for James's but didn't see him. He didn't see Peter either and began to worry that James had told Peter what had happened before he'd gotten a chance to talk to him.

Not long after dinner Peter came in and gave him a small frown. "Hi Sirius." He said uncomfortably.

Sirius leaped to his feet. "Hey Peter, have you seen James."

Peter avoided his eyes. "No, Sorry. He came back to dinner but then he left again. I haven't seen him since."

"Did he say anything?"

Peter hesitated. "Listen, I'm really tired. I think I'm just gonna get to bed." He hurried pasted Sirius, leaving him feeling miserable. Once Peter was gone he threw himself back down in the armchair and sighed, determined to stay up and talk to James.

So this was a pretty big chapter and it took me forever to think of a situation in which Sirius would tell Snape how to get under the tree but I eventually decided on a scenario where Sirius was being kind of smug and arrogant a it just kind of pops out. I'm not entirely pleased with it but I think it works so anyway. Thanks for reading!