Fili manifested the Aching much younger than other dwarves his generation did. The first time he felt it, it had only been a strange itching at his chest and he had paid it no heed, returning to his studies while Kili lounged next to him, bored. The next time he felt it—before dinnertime over a week later—he had doubled over in pain, feeling like an arrow had pierced his heart.

The plates he was setting up the table with crashed to the ground and splintered into fragments, his bare hands flattening against them in an effort to hold himself up. Shards embedded themselves into his skin and yet he felt nothing, heard nothing; there was only the wide, gaping hole in his chest where his heart used to be whole. He saw Kili yelling and his mother hurrying towards him, but he couldn't right himself. Fili couldn't move if he wanted to and even breathing hurt.

Dis, slight as she was, picked him up from the ground with the strength and love a mother would muster for her child. She settled him on his bed in his room, Kili trotting after her with wide, wet eyes.

"Fili," he heard her say, her voice sounding garbled and distant. He barely recognized his own name.

She carefully cleaned his hands and wound it up in neat white bandages. Dis spoke to him, her cadence slow and steady, but Fili only heard the sounds and not the words. There was a hole in his heart and half of him was missing and there was nothing in the world that could make it better.

He didn't know how long he sat there, but when he could move his limbs once more, he noticed the blanket that's been put over his shoulders and the low light in the room. The door was opened and there was jumbled sounds coming from outside it.

Though the pain in his heart had lessened, it still made itself known in the most vicious of ways; every breath he took was cold and freezing in his lungs, his mouth tasted of blood, and his head pounded fiercely.

"Fili?"

He looked at the lump next to him. Kili stared back, his dark eyes shining wet in the darkness.

"Kili," Fili managed to rasp and his brother wrapped his arms around him. It was painful to touch, but he couldn't move very much and the embrace was welcomed over the endless pit of loneliness that spanned his heart. He managed to put his arm around Kili, his whole body protesting, but he forced it to listen to him. "I scared you," he said. "I'm sorry."

"No," Kili said, shaking his head. "Does it still hurt? Are you still in pain?"

Fili took in a breath that rattled around in his chest. "Yes. Let me sleep a while. I'll feel better after."

"Really?" Kili sounded so frightened. "Do you promise?"

Fili considered. "Yes. I promise."

After the Aching had passed, it was the Waiting and for the start of that, Fili had felt strangely light.

"There is someone fated for you," Dis had said and Fili had smiled to himself at that. Even though a faint throb of pain in his heart remained, nothing could take away the elation that there was someone in the world that had his piece of heart. Since he did not feel his heart being Mended, it meant that his fated had not yet matured. When his heart was returned, it would lead him to his fated and Fili wondered who it would be.

It would be a dwarven maid, he decided to himself, with dark locks like his mother and Kili and Thorin. She'll be strong too, and fun.

"How long did you Wait?" Fili asked.

Dis smiled patiently. "Two whole years," she said, pressing a kiss to his temple. "Although I did not manifest the Aching as young as you did and times were different then." She looked sad at that, but Fili continued to smile happily at nothing.

Years went by and Fili turned from twenty-five to thirty, to forty, to fifty. The Waiting lasted ages and Fili was beginning to depress at ever getting his heart returned. He could grow a beard now and drink mead without it going straight to his head.

His fated had changed many shapes over the years. Gone was the childhood imagination of a dark haired woman, replaced by a fiery red head, and then a warrior with an impressive beard. It had been a time since Fili had last imagined how his fated would look like and somehow, he found himself envisioning a dark haired dwarf that liked to laugh.

"Maybe your fated is just a late developer," Kili said. He tended to dislike the topic of Fili's fated and today was no exception.

"Like you?" Fili sniped.

Unlike Fili, Kili still hadn't experienced the Aching, the separation of his heart in two. He knew that despite the laughing façade, Kili was starting to get worried. They knew that some dwarves were born fated to be alone and they were dedicated craftsmen, artisans of the highest caliber. But never had it been that way for the line of Durin and Fili couldn't see how his brother would survive on his own, not when he and Fili rarely left each other's side. He needed someone to ground him and Fili hoped that Kili's fated would give him everything he needed.

"I am just taking my time," Kili retorted and Fili rolled his eyes, fond.

When Fili turned sixty, he wondered if his fated was dead. He said as much out loud to his mother and Thorin, who had exchanged exasperated looks behind his back.

"If your fated was dead, you'd know," Thorin said at last. "There are some who have waited sixty years for the Mending. There's no need to be so impatient."

"But how would I know?" Fili pressed.

Thorin sighed. "They possess half of your heart. If they die, your heart dies with them."

Fili pursed his lips and was about to comment when the front door burst open and Kili was striding in, ink all over his face and a furious Dwalin following after him. The topic was forgotten in favor of laughing at Kili's attempt to imitate Dwalin's tattoos.

The day Kili manifested the Aching had been an auspicious one; the weather outside of Ered Luin was terrible and stormy and within the mines, an accident occurred, nearly killing three dwarves. Fili was with Kili at the training grounds, practicing swords when his brother froze, expression full of shock, and collapsed in a heap.

Fili rushed to him immediately, concerned. He hadn't expected the Aching; Kili had given no sign.

He had just barely helped Kili up from the ground when the sensation of being hit in the chest with a hammer knocked him over. Kili moaned, a hand fisting into his shirt over his chest.

"Fili?" Kili called.

There was a warmth spreading through him, a feeling that he hadn't experienced in years; his heart was whole again, the empty loneliness receding. He knew who held the half of his heart that left all those years ago.

"Kili."

Kili sat upright from where Fili had unceremoniously dropped him on the floor. He was surprised, his eyes large and bright in the lamp lights. "Was that…was that it?" Kili asked, though his voice sounded soft and far away. His hand still clutched at his chest.

"Yes, and no," Fili replied, gently uncurling Kili's fingers from the fists they formed. The faraway look in Kili's eyes disappeared the moment Fili touched him.

"It's you," Kili said simply.

Fili hesitated all of a sudden, panic swirling through him. Though it was rare, siblings had been paired off together before. But what if Kili didn't want him? Fili wasn't going to deny that he never thought of Kili as a possibility; his imagined fated ran through his head as a maiden, dark haired, then red, then dark again, then becoming manlier, stouter, ever evolving. The one in his mind had never settled on Kili, though in retrospect, the ones that he thought up always had some quality of Kili's.

"Yes," Fili said softly.

Kili smiled, dazzling and warm and inviting. "I knew it was going to be you," he said. "I knew it."

"You don't object?" Fili asked.

"Object? Why?" Kili pressed a hand to Fili's cheek, forcing them to make eye contact. "I am beyond happiness."

Kili leaned forward and kissed him, soft and sweet. Fili's heartbeat was loud in his ears, almost a rhythmic roaring, and it felt like his chest would burst with joy. He smiled, cupped the back of Kili's head, and kissed him again.