I hope you enjoy! Bunny's and North's accent is not written in. You'll have to imagine it! Also no pairings. Don't like, don't read!

Summary: Jack enjoyed his new life with the Guardians, but we all have secrets. Jack is the spirit of summer, winter and music ever since his sister disappeared. Voldemort has teamed up with Pitch and they are all sent to Hogwarts to protect the children there… But no one knows that it's more on stake than just protection. Will Jack's long lost sister be found or will he be gone forever?

Jack was enjoying himself in the woods of the borders of Finland and Sweden for a few moments before it was time to spread summer and write new song texts. This had kept him busy for 100 years before the Guardians. It was then his sister disappeared. No one knew where she was, so Jack was forced to take her role as the spirit of summer even though he was the winter sprit and the music spirit already. The other spirits said that they were too busy with their job and they had one job, not two like Jack had. But not one of the spirits gave him a chance to speak and now he was a Guardian and a spirit of three things!

Sounds tough? It is tough!

Jack looked at the night sky and saw something troubling. The Northern Lights were travelling through the star-filled night sky. The humans thought it was beautiful, but to Jack it meant meeting at the pole. And a meeting at the pole could be both good and bad. Jack sighed and hoped for the latter when he asked the wind to take him to North's workshop.

Jack was the last one to get there and when he came in he had "activated" his ice powers. A cold wind came through the window he flew through.

"Can't you make warmth, frostbite?!" Bunny complained with his Australian accent. The other Guardians ignored the comment and Jack just smirked. If he only knew how close he was to the truth…

"Ah, Jack" North said. "You're finally here. Manny sent us letters!" he showed them all five letters. One had an Easter egg on it; one had a tooth on it, a plane made of dreamsand and a snowflake. Well, the last one had half right. It was a snowflake in a sun with dark blue music notes one. Luckily the others ignored it. North gave them all their letters. "I open first!" He opened his letter that had a gift on it. He read it for them.

"Greetings, Guardians!"

"I have something very important to say. Pitch Black has teamed up with the Dark Lord" "The children on Hogwarts are in great danger and they'll need help. That's why I send you to the school to attend a year."

"But you'll need to do it incognito. North you'll be the father of the Moon-family and" "you'll be the new teacher in astronomy and you'll have the name North Moon."

North finished reading with an 'Hm' sound and pointed at Tooth.

"Now it's you!" he said in a funny way and she laughed as she opened it.

"Ok…" she began.

"Dear Tooth"

"You'll pose as the muggle studies teacher at Hogwarts and be the mother of the family. Your name will be Annabelle Moon, or just Annie for short. I'll have a potion ready for you later. North will give it to you after reading the letters"

"Sandy" Tooth said when she finished reading. "Do you want me to read it loud?" Sandy nodded and gave her his letter.

"Dear Sandy"

You'll pose as a student in the 4th year and you'll need a potion too for disguise and talking. North will give you a potion that'll do just that. Your name will be Sam Moon"

North shrugged and pointed at Bunny.

"You" he said. Bunny rolled his eyes and opened his letter.

"Bunnymund"

You'll pose as a student in the 5th year. You'll need a more human like appearance and North will fix it. Your name will be E. Aster Bunnymund and you were found on the streets 5 years ago. You never met your parents and were taken to an orphanage, but you ran away 6 months later."

Bunny finished reading and then looked at Jack, a smirk growing on his face.

"It's your turn, Jack!" he said with a fun voice.

"Ok, but first I have to say…" a smirk grew on Jack's face. "Your story was so adorable!"

Bunny glared at him. Jack opened the letter and gave the paper a quick look before starting to read. He was better at reading than any of the Guardians.

"Jack"

"You'll pose as a student in the 3rd year and be responsible for the most important thing. You need to protect the child named Harry Potter. Your name will be Jack Frost Moon. Your parents died in a car crash and the family took you in from the streets where you discovered your elemental magic. The Moon family discovered that you had a special talent with music and you were soon known to the world as the singer "Jack Frost". Your next concert will be at Friends Arena in *Sweden the ninth of October so never forget that. I've sent a list for each one of you. It's a list of things needed at Hogwarts. Good luck Guardians!

P.S I will do your duties, Jack."

Jack smiled at the text, but then looked at North.

"Potions?" he asked with a raised eyebrow. North nodded.

"Here you go!" he gave them a potion each. They were all colorless. North drank his. Confetti swirled around him and when he was transformed he had shorter hair and beard. Jack gave thumbs up with a big smile. Tooth drank hers after North. Colorful glitter surrounded her and when it was done she had a turquoise tank top, black jacket, pink jeans and black combat boots. Her hair was black and had trips of pink and yellow and was in a tough haircut. She had makeup in black, blue and green. Jack made sure to comment that the new outfit were "so awesome!". Bunny drank his. Green smoke surrounded him and when it was gone a human version of Bunny stood where the Pooka once stood. He had a yellow t-shirt, blue jeans with a chain, blue sneakers and bluish hair. He also had dark grey tattoos were the marks were. Sandy drank his potion and dreamsand surrounded him. When it was done he was Sandy with slightly tanned skin, same clothes, but in clothing and not dreamsand. Now it was Jack's turn.

"Can't believe I'm always the last one" he muttered before drinking it. A small blizzard formed with small snowflakes, suns and music notes. When it was gone Jack had a blue t-shirt, a white jacket, but he also had yellow jeans with a chain in light blue, his hair was a mix of brown and white and he had light blue sneakers. His left eye were blue and the other were deep brown.

"Cool!" he said. "How do I look?" The Guardians looked at each other and nodded. "Should we go to… that place you never mentioned to get our weird things we didn't know exist?" North's eyes widened and while the man answered Bunny rolled his eyes.

"Of course" he said. "It's in Diagon Alley. Just walk through the fire" he threw some powder in the fire and it became big and green. Jack stared at North, but then shrugged and before they could do something about him he had walked through.

"Jack!" Tooth shouted with a bewildered look. North rushed forward to calm her down.

"Calm down, Tooth, he's fine. That's a portal" he said and Tooth immediately calmed down.

"Oh" she said, and then laughed nervously. "Sorry" North chuckled and made a gesture for her to go in while walking in himself. The three remaining Guardians soon followed.

[THISISANEVILLINEBREAK]

Everyone was soon in the beginning of Diagon Alley. Bunny was pale and glared at the other spirits that laughed at him.

"Not so brave, huh, kangaroo?" Jack said. Bunny kicked the ground.

"Shut up, frostbite!" he said. Tooth patted Bunny on the back.

"Don't fight when we're here! It's rude" she lectured.

"Okay Tooth" they both said. They walked to Gringotts bank to get some money first. Then they walked to the first shop for some school uniforms. In there, Sandy, Bunny and Jack had to stand still to not get a needle in their butt. The next stop was to get their books and it was North who took them when they had payed for them. Then they walked to Olivander's and got a wand.

"Apple, 12½ inches, dragon heartstring" the old man said when he gave Bunny a wand to test. "Wave it" Bunny waved it and a lamp exploded. He winced, but Olivander just took the wand and gave him a new one. "Now this one, Raspberry, 13 inches, unicorn hair, good with transfiguration" Bunny gave it a wave and colorful mist that danced around as a snake in the room before dissolving in a shape of a flower. The wand was a greenish brown and had a dark green handle.

"Green, huh? It fits, right kangaroo?" Jack said, earning a glare from Bunny.

"That's the one!" Olivander said and put the wand in its package. "Now it's your turn" he pointed at Sandy. "I am sure about this one. Pine, 12 ½ inches, unicorn hair, good with charms" Sandy took the offered wand. It was light brown and had lighter patterns as dreamsand all over it. Jack gasped in wonder when dolphins made of dreamsand came out of the wand and circled around them before fading away. After Sandy it was his turn. Jack frowned as he gave his staff to Tooth. Wands are useless, but my staff is not!

"Now I think this is the one, Dragon's Blood tree, 12 ½ inches, frost core, and good with charms, transfiguration and Defense against dark arts. The only wand that is good at several things. Now try it" Olivander said and carefully gave Jack a wand. Its handle was brown with red speckles like someone had thrown red paint at it and the rest of it was dark blue. And if you looked closely you could see the pattern of suns and music notes in the space between the handle and rest of the wand.

Jack gave it a wave and a swirl of frost came out of the wand along with the smell of summer and the sweet sound of a flute.

"I'm impressed... In all my years I've never seen such a thing happen. Here you go, the box and remember that you can't use magic all the time even if it's tempting" he said with a smile, a spark of mischief in his eyes. Jack chuckled and the three "brothers" walked out of the shop with their wands in the boxes. They waited on a wooden bench outside while Tooth and North payed for them. Bunny looked at Jack's box.

"Frostbite, what happened in there?" he asked referring to the fact that three things happened and two of them shouldn't have happened at all. "It was weird" Jack sighed.

"Well…" he began and Bunny and Sandy leaned closer. "I think it's better to explain when North and Tooth are here" the two pouted.

When they were at the pet shop they were allowed to pick a pet to be with them at all times. They had exotic birds, owls of all kinds, toads, rats, mice, cats and even dogs! Bunny was the first to find his. He wanted a pigeon. The light reflected at the bird's neck in a green and purple color and it was mostly grey.

"What will you name it, kangaroo?" Jack said with a grin on his face. Bunny glared and petted his new bird that sat on his shoulder.

"I don't know, frostbite" he said back. "Maybe… Astrid! Don't you dare, Jack!" Jack, who held his hands to cover his mouth nodded, but you could still hear the laughter that escaped his lips.

"Sorry" he said when he calmed down and took a deep breath. "I couldn't hold it!" And before Bunny could do anything the winter spirit had hid behind the cages.

Then Sandy found his pet half an hour later. It was a golden colored owl with brownish beak and yellow and intelligent eyes.

"Looks just like you" Jack said with his famous half-grin on his face. He earned a friendly punch on the shoulder from Sandy. "OW! HE PUNCHED ME!" Jack then said dramatically and grabbed his shoulder like he was in pain. The 'family' laughed at him. Tooth and North shared a white and exotic colored parrot. How the combo was made was nothing that they wanted to know.

"That bird is awesome" Jack commented before he left to look after his pet. But after an hour he still hadn't found the one. His companion seemed to be nowhere. They had checked every cage, but Jack didn't like them.

"Jack" Bunny said when they sat down on a bench between the cages. "Maybe… There is no animal for you…" Jack sighed and looked at his new brother with sad eyes before turning his eyes on a window.

"Maybe not" he said. "But I know that he's here somewhere. We just… haven't… found him yet" the winter spirit leaned his head back and closed his eyes, taking a deep breath to calm his sudden anger. "Because of his many… jobs his eyes tended to change color when feeling different emotions. His eyes were orange now 'cause of his anger. Keep looking! He told himself and after a few seconds he was sure that his eyes were blue again. The shopkeeper seemed to have heard what the two brothers talked about and came forward.

"I heard you can't find your companion, boy" he said with gentle eyes. Jack looked down in shame. "It's nothing to be ashamed of… In fact, I think I know someone who you would like to meet, but he's not here. He's somewhere else… Follow me!" The shopkeeper waved for him to come with him and Jack followed. Bunny stayed back to tell the others that he was… elsewhere.

Jack followed the man to a door in the back.

"We've a special animal in here and I think he might like you. I'll let you in, but I can't follow you" the shopkeeper whispered to Jack and opened the doors lock. Jack placed his hand on the handle and took a deep breath. It's now or never.

He opened the door just enough for him to get in and then the door closed behind him. What he saw made him gasp.

The room was empty and dusty. The room was very big and the light was only directed at the middle. There stood a rusty cage and in it was a fluffy dog, so dirty that you barley could see that it was white. Its eyes were fire colored and it looked at Jack when the winter spirit entered. It began to growl and stood up in a threatening position.

Jack slowly approached it. His feet didn't make a sound. When he was 5 meter's (a step forward times 5) away the dog stopped growling and just observed him. When the winter spirit was beside the cage he sat down with a sigh.

"Why are you in a cage?" he thought aloud. The dog gave him a sad look. "You don't seem to be dangerous." Jack stepped closer and petted the dog through the iron bars of the cage. Jack kept on talking with it 'til the other Guardians came in with the shopkeeper first.

"See?" the man whispered. "They are right for each other" Jack looked at him.

"Why is he in a cage like… this?" he gestured to the cage. The shopkeeper sighed.

"He was so violent that we couldn't keep him there and I didn't have the heart to kill him. He already had a name and everything and it felt so wrong to kill him" he said. "The dog's name is Dubstep. A muggle-born boy named him because he thought it was unfair that he didn't have a name. But I see that he's the one for you, boy, so why don't you take care of him for me. He'll be much happier with you" Jack smiled.

"Awesome, but give me the keys then" he said and the shopkeeper sighed before taking a pair of rusty keys and tossing them to the winter spirit. Without a second thought Jack let the dog out. The dog stood there for a moment, unsure of what to do with its new freedom. It then slowly took steps out of the rusty cage.

When it was out it rushed to Jack and licked his face with its wet tongue. He laughed.

"It tickles!" Jack managed to gasp out before he kept on laughing. The shopkeeper was both chocked and happy. The dog had never been so happy before. They were meant for each other.

"We better give him a bath" The shopkeeper said.

:.:.:

While the shopkeeper and the other two people working at the store gave the dog a bath Bunny and the others demanded their answer from Jack.

"Jack can you give us an explanation now!" Bunny said, crossing his arms. Jack looked around, meeting the Guardians' eyes with a nervous face.

"Uhhhh…" he said, hesitating. "As all of you know, a spirit needs another one to do the spirit's job when they…die…" North laughed.

"And why do you say that?" he said. Jack gave him the serious face that Jack almost never had.

"And you all know that a spirit has two things to be the spirit of when they're… born and well… I'm one of them"

"But over what? And I've never heard of a spirit that was actually born that way!" Tooth said, tilting her head to the side.

"I was born as the spirit of winter and… music, but… when I was about two hundred years old my sister just as old as me just… disappeared. She was the spirit of summer and when a spirit meeting was held about who would replace her they all said that their one job was too much already. They didn't even ask me before making me her replacement. That's why I always was late to meetings. I had to be everywhere on earth at the same time and give the world music! I'm still tired from last run!" Jack said.

"What?" Bunny said. He stood up in surprise and anger. "That's wrong to do!" Jack sighed and his eyes changed color to green.

"Say that to all the spirits in the world! Including you…" he said, and then looked at something moving towards them. "Looks like they're done with the bath"

"Your eyes" North said. Jack nodded. He had felt his eyes change.

"I know… Come on" And with that they left the shop with a white dog following them.

Then they got everything else before going to the Leaky Cauldron where they had two rooms with separate beds and slept all night…

I mentioned Friends arena in my own country because I don't know any other place that he could possibly have a concert on. This will be songs in this fanfic, but they won't sing their conversations or so like in a musical, I promise!

I hope you enjoyed this chapter and plz read and review. You can also fav and/or follow if you liked it. Suggestions are welcome since I prefer to listen to my readers and use suggestions they write to me.

I'm sorry if my grammar is bad. English isn't my native language!