Everything belongs to Jk Rowling.
Remus watched as James playfully shoved Sirius sideways. He was not exactly jealous of their friendship, he admired it really, and he knew that half breeds did not deserve proper friendship, but he could not help but wish he could have that too.
Sirius stumbled into the classroom near them, and they walked into it. It was deserted, and clearly abandoned. There were several similar classrooms in Hogwarts, perhaps when it was built the founders had expected more students.
Remus, James, and Peter followed him into the room. The corners were rather dusty. A large cupboard full of supplies was in the corner of the room. James walked over to it, and pulled it open. Suddenly something fell out of it. Three dead bodies. Lily, and who Remus presumed were Mr and Mrs Potter. James let out a shreik of fear, and leapt backwards.
Sirius walked over there to investigate, and the bodies changed. The stood up, and turned into a woman who had to be Sirirus' mother. She bore a striking resemblance, though she had a much harsher expression. She raised a wand, and pointed it at Sirius. Remus could see the fear that seemed to have frozen Sirius.
Peter watched what was going on with interest, and stepped forward. As he did, Mrs Black changed, turning into Peters dead body. Remus did not know what was going on. He stepped forward, wondering how to help. As he did, Peters body changed into the pale orb of the full moon.
Remus gasped and stepped back, trying to swallow down his fear. It wasnt real. He wouldnt turn. He wouldnt change into the wolf. He wasnt about to kill his friends, he just couldnt. The moon had to be a fake. Remus wouldnt survive killing his friends. If the ministry didnt decide to have him put down, his father would kill him. And, if they both decided not too, Remus would kill himself. He had made his mind up on that years ago. He would not hurt a human.
"Ridikulas" Sirius suddenly yelled. The moon turned into a balloon and floated around the room, letting out air. "it was a boggart." Sirius said. "it shows people their worst fears. My mother left me in a room once with one."
Remus slumped to the floor. he leant his back against the wall. The boggart wasnt fully right. True, Remus did fear the full moon, but under that, he did not want to hurt the people he loved. He also did not want to be alone. Desperately, he longed for friendship, for Romance, for simple things that humans took for granted that were not offered to werewolves.
"it got mine wrong though." Sirius whispered. "i fear dementors more than her. The way they make you relieve your worst memories. I fear being sent to Azkaban, surrounded by dementors, all the time..." Sirirus trailed off.
"it got mine wrong too." Remus whispered. "the thing I fear most of all is being alone." Sirius looked at him. "you won't ever be alone. We'll always be there for you." Remus doubted that, though he said nothing.
"Well, it got mine right" James said. "lily and parents dead" Peter nodded. "yeah. I dont want to die, and it showed me dead." he said. Sirius shivered. "its a funny thing, fear." he said. Remus remembered the passage in his book about fear.
Fear is unique. Everyone is scared of something. Fear protects us. Fear lets us know when something could be dangerous, and warns us not to do it. It is almost never acceptable to tease someone about their fear. They cannot control what they are scared of. Mind you, if they are being homophobic or transphobic or lycanthrophobic, or something along those lines.
In those circumstances they arent scared. They are just arseholes. They use the excuse of fear to justify their hate. In those circumstances, its perfectly okay to tease them of their fear. Be as gay or trans or werewolfy as you want, because it isnt a real phobia.
Remus nodded. "fear is powerful. And if we dont control it, it controls us. Maybe the thing we should fear most of all is fear itself."