Long before he got to the house, Thorin could hear the noise. The house he shared with his sister was set back and away from the colony that had begun to grow in the Blue Mountains. Many, when they first arrived to join the others, thought that it was because they were the last of King Thror's line, that as royalty they couldn't be living alongside the common folk. It only took a single morning for them to realise this wasn't the case at all.
This wasn't even the first house they had lived in. At first, they had lived much closer to the centre of the small village, near the people who had followed them here. They had wandered the wilds for so long that they were all a family now and space wasn't a thing they understood. He had watched as his sister had found a male worthy of being her husband and rejoiced with her when her first son had been born.
Fíli had been an even tempered child, always willing to please even as a baby. He was easy to settle and hadn't been bothered by the bustle of the dwarves around him making new homes for themselves. He had been content to sleep away the hours in the arms of his family, waking only to make adorable noises at whoever happened to be holding him. He had the blue eyes of Durin's line, the colour as clear as the finest sapphires found deep within Erebor. The blonde hair was different though, a gift from his father since Dís was as dark haired as Thorin. But he was treasured greatly, not only because he was family, but because he was more proof that the line of Durin would continue.
Five years passed with Fíli growing into a fine young dwarf who played well with the other children and was always willing to help. He would fetch rags for his uncle to wipe his brow while he was forging or water for him to drink. Granted, the rag was usually dirty and the cup nearly empty by the time either reached him, but Thorin never once complained about the help. Fíli was his sister-son and was more important to him than he could ever say aloud.
Then his sister had blessed their family with another son, Kíli, and everyone had swiftly realised that this baby was not like his brother. From the moment his dark eyes had blinked open, Thorin had sworn that there was mischief in them. And Kíli had seemed bound and determined to prove his uncle right. He would wail unmercifully if someone wasn't holding him while he was awake and when he was being held if you weren't doing it properly, he would squirm until you nearly dropped him. The only person who seemed to be able to hold him perfectly turned out to be Fíli, but at five, the young dwarf couldn't hold his brother for long before he had to stop. Which in turn made the baby howl even more.
Things only got worse once Kíli managed to get mobile. He was always underfoot, clinging to boots and ankles and squealing in delight as he was dragged across the floor by the one he was holding. He had started hiding things, taking spoons from the table and stuffing them under cushions or shoving cleaning rags into Dís' vases. But no matter how hard you tried, you couldn't stay mad at the boy. He would plop down on the floor and stare up at you with his big dark eyes. Even Thorin, who had sworn he wasn't going to pamper the boys, couldn't stay mad at him when Kíli gave him that look. The young dwarf had mastered it quickly and it was a good thing too because he wouldn't have lasted long if he hadn't.
Everyone had hoped that because the two boys were such polar opposites of one another, they would balance each other out. And they did to a degree. As Kíli got older, he wanted to be more like his brother, but the older Fíli got, the more mischief the two of them got into together. The two were inseparable now, sharing a room and all of their play adventures. But while they were usually as close as brothers could be, every now and then, one of them rubbed the other the wrong way.
Their first spat had caught everyone by surprise and it had taken a long moment for the adults to realise that the play fight wasn't play anymore. Thorin had grabbed Fíli and Dís had snatched up Kíli, but the two dwarflings had squirmed and struggled, trying to get back at one another. When asked, neither of them could remember what had started the fight and the threat of separating them had resolved it quickly. But the fights still happened between them and were the real reason the royal family had built a house a little apart from the others.
Lengthening his stride as the noise became loud enough for him to make out the high pitched shouts, Thorin wondered what had set them off this time. It was still early in the morning. They couldn't have been up for long and probably hadn't even finished breakfast. He had been called away in the night to help fix a bridge that had collapsed and coming home to a fight was not what he wanted.
The door slammed into the wall as he thrust it open and it made the two dwarves jump in fright. Two pairs of eyes swung to look at him and two lower lips quivered. "That isn't going to work," he told them sternly. "You're ten and five now. You're too old to be bickering like this. I don't care what was said-"
"Fíli said I'll always be short!" Kíli blurted, his voice still loud.
"You're a dwarf!" Fíli threw back at him. "You're supposed to be short!"
Thorin gave a growling sigh. This was really what they were fighting about? "Dwarves are not short," he told both of them. "We are the perfect size and everyone else is wrong."
Kíli's lower lip was working overtime as it started quivering again. "I'm always going to be small?" he whispered.
Apparently his height had become a sensitive thing for the young dwarf. Yes, he was smaller than Fíli had been at that age, but he was still only five. "Fíli is five years older than you, Kíli. You can't compare yourself to him. One day, you'll be as tall as him."
Kíli sniffed and looked at him with watery eyes. "Promise?"
It wasn't something he should promise, but those of the House of Durin were usually taller than the average dwarf. Kíli would have a growth spurt soon enough, but he would likely forget this matter before the day was over. "Perhaps you'll even be taller than him."
Kíli's eyes got big and Fíli puffed up. "He will not! He's my little brother and he's supposed to be littler than me!"
Sensing another argument, Thorin growled at both of them and it made them both freeze. "Both of you are going to stay little if you don't stop fighting."
They stared at him. "What do you mean?" they asked together.
"Family is supposed to work together, not fight with one another like this. If you do, you'll both stay the size you are now and never grow."
Shrill cries left both of them and they grabbed onto one another. "We never fight again!" Kíli cried.
"Promise, Uncle Throin! We'll be good!"
Thorin wanted to believe them, but they had promised before and forgotten as soon as one of them made the other mad. "Good," he still said. "Now, I'm hungry and it smells like your mother is making breakfast. If you're both good and eat properly, I'll tell you a story."
The squeals that left them were happy this time and tugged a rare smile from Thorin as they raced over to hug his legs before running off to find their mother. The fights would continue between the boys, but Thorin hoped it stayed at this silly level and never became more than that. Because family was more important than they realised yet and once you lost them, they never came back.