This one roughly corresponds with Chapter 14 and portions of Chapter 15 in the Philosopher's stone, but there will be a few twists in here. It does deviate from canon a fair bit, but it still makes the alternate timeline story plausible.
Kellen enjoyed spending his twelfth birthday with his friends. Some of his professors remembered to wish him a happy birthday (namely Professor McGonagall and Professor Flitwick). Even Malfoy breathed a quick "happy birthday" after Potions. Hagrid even brought over a baseball-shaped cake to the Great Hall for dinner.
The next few weeks were relatively uneventful. The Easter holiday was soon approaching, meaning that the end-of-year exams weren't all that far away. Hermione was fretting and doubling her already-considerable efforts in her studies; she had tried to get Harry and Ron on board, but Kellen convinced her that he was capable of ensuring that Harry and Ron were where they needed to be without all that ridiculous additional preparation she wanted them to do. After all, he had a knack for teaching things to them in a way she couldn't.
He made flash cards, used mnemonic devices, and taught them the Feynman method - better known as the "teach it back" method, and Harry and Ron even acknowledged that Kellen's study aids were making a sizable difference, they were grateful for someone like Kellen who was able to effectively relay the material in an understandable way, and make it stick.
One morning in early March, Hagrid owled Hermione about the dragon egg - it was starting to hatch! Ron had argued with Kellen about whether or not to skip Herbology, but Kellen assured Ron that he did some recent research on dragons and that hatching is hardly an instantaneous process - they should have plenty of time to attend class and then pay Hagrid a visit during their break. Hermione gently admonished Kellen and Ron to keep their voices down as they bantered so they could avoid any unwanted attention.
During their morning free period, Hermione, Kellen, Harry, and Ron went to Hagrid's hut just in time to see the dragon emerge from the egg.
"Aw bless it, it looks like a Norbert," Hagrid beamed. He rubbed a finger on the hatchling's snout. "Who's your mummy?" he chuckled playfully. He fetched a bucket with a rather vile-looking concoction - brandy mixed with chicken blood. Harry pinched his nose in disgust after he inadvertently caught a whiff of the mixture.
The children visited Hagrid and Norbert faithfully after school each day, and were astonished at how quickly it grew. It had more than doubled its size in just a week's time.
Ron threw Hagrid a look of concern. "I know you're attached to Norbert, but he's going to be getting too big for your hut in just a few short weeks," he said.
"I know you once told me that you always wanted to raise a dragon, but you're just not going to be able to keep him forever," Harry added in a commiserating tone.
"You might be able to hang on to him for another week or so," Hermione chimed in. "But in the meantime, you're going to need to figure out where he's going to go."
"I think I have an idea," Ron said. "Charlie's off studying dragons in Romania, I'm sure he'd be glad to take him on."
Hagrid sniffled some. "I know yeh're right, but... but... I'm just worried that the other dragons won't like Norbert too much. What if they make fun of his snout?"
Kellen chuckled. "I highly doubt that'll be a problem.
Hagrid sniffed again. "All right, Ron. Go and owl Charlie to see if he can take Norbert." He blew his nose with a handkerchief.
Hagrid and the Gryffindor children spent the next several days waiting for Charlie's reply via owl. They took turns helping Hagrid feed Norbert - one night Hermione and Harry would don Harry's invisibility cloak and sneak out to Hagrid's hut, then the next night Kellen and Ron would do the same.
One night, it was Kellen and Ron's turn to help Hagrid feed Norbert. The dragon had certainly gotten bigger, and if anything, more dangerous. It wasn't necessarily mean-spirited, but it was certainly large and had a mind of its own. When Ron tried to feed Norbert a dead rat, it inadvertently bit Ron's hand, causing him to shriek in pain.
"According ter the book that I borrowed from Madam Pince, Ridgebacks do have some venom, Ron," Hagrid said. "Yeh'd best be headin' ter the infirmary first thing in the morning."
"My mum's a veterinarian," Kellen said. "She keeps some of this on her person at all times for emergencies like this. This should not be confused with an actual antidote, but it'll at least help buy time to get to Madam Pomfrey in the morning." He pulled out a small vial of petroleum jelly from his pants pocket and liberally lathered a glob of the creamy goo on Ron's hand.
"I never thought I'd be so grateful for Muggle artifacts," chuckled Ron. "Thank Merlin you're so resourceful, Kellen. It doesn't burn as bad at least. Thank you."
Kellen helped Ron wrap a makeshift bandage around his hand, and the two bade Hagrid and Norbert farewell for the evening. They donned Harry's invisibility cloak and returned to the common room.
"Good news, you two," Harry grinned at Ron and Kellen. "We just got a reply from Charlie in Romania. He'd be happy to take Norbert off our hands. He has some friends that will be meeting us at Hogwarts in a few days, so we just gotta keep doing what we're doing a little bit longer."
"Perfect," replied Kellen. "Best news I've heard all evening."
"Ronald," gasped Hermione, pointing at Ron's bandaged hand.. "What happened to you?"
"That stinker bit me when I was trying to feed it," Ron grumbled. "Thank Merlin Kellen is such a quick thinker. He put this strange Muggle goo on my hand which took some of the burn away."
Kellen produced the same small vial of petroleum jelly from his pocket.
Hermione arched an eyebrow. "Petroleum jelly? I'm pretty sure that's considered contraband around here..."
Kellen shrugged. "What they won't know, won't hurt them. Besides... Ridgebacks apparently have a bit of venom in their bites, so it'll protect his hand some until he sees Madam Pomfrey in the morning at least. It's not an antivenom, but it'll at least slow the progress a little, and furthermore, it'll cool that burning sensation and keep his bite from getting infected. His hand could swell really, really bad without it. But I guarantee it'll still be redder than his hair come morning. I'll see him off to the infirmary."
"You can't tell her what bit me, can you?" Ron pleaded. "I don't want Hagrid to get in trouble."
"We'll only tell her what she has to know; nothing more, nothing less," Kellen said. "Go get some rest, Ron."
The next morning, Ron's hand looked much as Kellen had anticipated. It was only slightly swollen, but it was beet-red. Kellen escorted Ron to the infirmary right away, where Madam Pomfrey ordered Ron into bed right away, and shooed Kellen back to class. "Nothing I can't handle, Mister Grimseth. Your friend will be fine. Quite sore, but otherwise fine. You can see him after school."
During their shared free period, Harry, Hermione and Kellen discussed their plans for Saturday at midnight.
"Charlie's friends are to meet us on top of the Astronomy tower to take Norbert off our hands," Harry reminded Hermione and Kellen. "The cloak is likely big enough for just two of us plus Norbert, so one of you will likely need to stay behind."
"You should go with Harry, Kellen," Hermione said. "You're a bit more adventurous than I am, and have more of a penchant to bend - if not outright break - the rules, even though I will admit your reasons for doing so are always honorable."
Kellen grinned. "I knew you were going to suggest that."
Unbeknownst to them, their conversation had caught Neville's attention, who was walking past them. "'Scuse me, what are you all talking about?"
"Oh, hi Neville," Kellen said. "We're doing something for Hagrid."
Neville cocked his head. "Like what?"
Harry sighed. "I don't think you can handle the truth, Neville. I'm not saying that to be mean, I just don't want you to blow our cover," he said softly.
Neville's eyes narrowed slightly. "I caught something about Hagrid having a pet dragon. That's not just breaking rules, you know. That's banned per the Warlock's Convention of 1709!"
"I know," replied Kellen. "We've convinced Hagrid to let it go. We've arranged for someone to take Norbert of Hagrid's hands."
"And I know it involves breaking rules," sighed Neville. "I'm glad you're my friends, but I really, really want Gryffindor to win the House Cup. We've got the best chance to do it in years... and I don't want to risk losing points by you sneaking out and breaking rules." He shook his head. "Norbert is Hagrid's problem, you've got to find another way."
"There is no other way, Neville," Hermione countered gently. "We've already arranged for some friends of Ron's older brother Charlie to meet Harry and Kellen this Saturday night at the top of the Astronomy Tower."
Neville stood up, his face more resolute than any of his friends have ever seen. "You... you guys leave me no choice then. I'm grateful that you've told me to stand up for what I believe in, and I... I'm doing it now! I hate using your own advice against you, but... but it's for your own good! I'm gon... gonna tip off Old McGonagall. I'm tired of silly rule-breaking, so if you don't want to lose points, you're going to stay in bed this Saturday night!"
"Don't get your undies in a wad," Kellen whispered. "I mean, I'm proud of you for standing up for what you believe is right, and I certainly won't stop you from reporting us to our house head, but you also need to understand that sometimes... doing the right thing involves bending or even breaking rules." He looked into Neville's eyes.
"Look at me, Neville," Kellen said gently. "I promise Gryffindor is going to win the House Cup this year. But some things are also more important than house points... you remember what I did for Daphne and Pansy this year, I'm sure..."
Neville nodded.
Kellen continued. "And helping Hagrid find a new home for Norbert is absolutely the right thing to do. I lost us house points for saving Pansy, and she wouldn't be here today if I simply let the teachers handle it. Norbert's a dragon, Neville. A baby dragon that bit Ron - he's in the infirmary right now due to the bite. Imagine what a fully-grown dragon could do!"
Neville nodded again. "You're right, Kellen... but I'm still going to tip off Old McGonagall. I'm warning you, you ought to stay in bed..."
"Do as you must, Neville," sighed Harry. "I see there's no convincing you otherwise."
That Saturday evening, Harry and Kellen donned the Invisibility Cloak again and headed over to Hagrid's hut to take Norbert away for good.
"Buh-bye, Norbert, I'll miss yeh," Hagrid sniffed, as he blew his big red nose with a handkerchief. He nodded at the boys. "I know yeh're doing the right thing, boys, but I've grown quite attached to the li'l nipper."
Harry and Kellen were barely able to conceal themselves and the baby dragon inside the invisibility cloak, and made their way up to the Astronomy tower as directed in the letter Charlie wrote back to Harry.
The boys made their way up the Astronomy tower as quietly as they could - easier said than done with a travel-size dragon - as the time ticked nearer and nearer to midnight. They finally made it to the top of the tower with just a couple of minutes to spare, and at midnight on the nose, just as planned, Charlie's friends met them at the designated spot.
"Hello," Harry said as he took off the cloak. "I'm Harry, and this is Kellen. We've got Norbert. We're really glad you can take him off our hands."
"Nice to meet you, Harry and Kellen," Charlie's friends said. "Could you give us a hand with this harness, please? It's kind of tricky, even with the two of us. A couple of extra hands would be really nice."
Harry and Kellen assisted Charlie's friends with getting Norbert buckled up nice and securely, and just a few minutes later, Norbert and Charlie's friends disappeared into the starry sky.
Harry and Kellen high-fived each other and made their way back down the stairs, but to their horror, completely forgot that their cloak was left behind on the top of the tower, and when they reached the bottom of the stairwell, they were immediately met with a very vulpine grin.
"Heh, heh, heh," came a low, gravelly laugh, unmistakably from the sadistic caretaker, Mister Filch. "Professor McGonagall got tipped off the other morning, that a couple of young troublemakers such as yourselves might be out of bed tonight... you should have stayed in bed, I think..." His disgusting grin broadened. "I believe it's high time you boys paid the good professor a little visit. You can kiss all those hard-earned house points good-bye."
Several minutes later, Mister Filch brought Kellen and Harry to Professor McGonagall's office. She was in a green nightgown and wearing a hairnet. She had a particularly cross expression on her face.
"Thank you, Argus," she said with a yawn. "I'll take it from here." Mister Filch did an about-face and returned to the caretaker's quarters.
Professor McGonagall looked at Harry and Kellen sternly. "I'm very, very disappointed in you boys. What were you two thinking?" She cocked an eyebrow. "I'd wager that you weren't. It's twelve forty five in the morning, there is no reason whatsoever either of you should be out of bed. Now, I would be most appreciative if you could tell me what was going on."
Kellen swallowed hard. "I know this is hard to believe, but we had to escort Hagrid's pet dragon off school grounds, being that they're banned and all. I'm aware that we broke school rules, but it was the right thing to do..."
Professor McGonagall held out her hand, like a crossing guard would to prevent people from crossing the street. "Enough, Grimseth. To be brutally honest, it doesn't matter what your excuse is, or what your intentions were; the fact remains that you've had no business whatsoever wandering the castle halls after curfew."
"We don't care about what might happen to us, Professor," Harry added. "I just don't want Hagrid to get in trouble."
"That was Hagrid's problem, and he should have taken care of it himself," the Professor huffed. "But now, his problem became yours." She glared at the boys. "Sit down," she said sharply.
Her eyes remained fixed on her charges. "I regret to inform the both of you, that your careless actions have cost Gryffindor every single house point earned to date. All two hundred and fifty nine of them." She then arched an eyebrow. "However, as it stands, Gryffindor currently has ten points, as I have added ten back due to Mister Longbottom's honesty and integrity." Her expression softened ever so slightly. "I was really hoping that he would be wrong, because you two boys are truly Gryffindor's finest. I had expected so much better out of the both of you. If it were anyone else - with the possible exception of Miss Granger - I would have been somewhat more lenient as far as punishment goes, but I have to make an example out of you, despite my fondness for the both of you. And partly because of my fondness for the both of you. I just want you to know how serious I am about maintaining order, and I sincerely hope that this is the wake-up call you need... so, you both had better straighten up and fly right."
There was an awkward silence for a moment.
"Erm, is that all, Professor?" Kellen asked tentatively.
"Not quite, Mister Grimseth," Professor McGonagall replied. "In addition to losing house points, you will both serve a night of detention. You can expect details concerning your upcoming detention to be owled to you. Now - back to bed, the both of you."