"Where is Loki?" Thor frowned, glancing around the desolate training hall that his brother had seemed to take a liking to. It was quite odd for him to be absent, and it worried Thor more than it should have. Sometimes he feared he was just being too protective of his younger brother, but Loki was guilty of some horrendously brainless things.

Steve and Tony shot each other knowing looks, Tony chuckling quietly after seeing Thor's puzzled look.

"What?" The god tilted his head to the side in confusion, something he'd picked up unknowingly from Clint.

"He's in your room. Sleeping. Don't wake up up!" Steve raised his hand, causing Thor to stop. "He hasn't slept right since you left. The most he's slept, I think, was when we had movie night. Fell asleep right after we turned it on. Only time he's felt really safe, I think, and even then I don't think he got more than four hours of sleep. If you'd stayed away any longer, Clint was going to hold a mandatory Star Wars marathon. Whether it was for Loki's benefit, or to force Tasha to watch them, though, I'm not sure."

Thor paused, trying to digest the information, still adjusting to the Midgardian language. Too modern for his taste, but Loki spoke it fluently, and he would do anything for Loki. "Has he not been well? I mean, is he ill?" he paused for a moment, trying to think of the correct word. "Sick! Has he been sick?" His face lit up with pride as the word slid easily from his lips. Loki would be happy he was doing so well with the language. He could almost go out in public without getting odd looks.

"Love-sick." A smirk slid onto Tony's face, but it quickly slid off when he was elbowed in the ribs by Steve. "I mean, he's missed you. A lot. I think he's been throwing up. He's lost weight. And I can hear him crying at night. He's terrified, Thor, but I don't know what of. "

That time, Thor left despite their protests. If Loki was sick - and it was his fault - he would never forgive himself. "Loki-ki?" he murmured, tapping lightly on the door. A relieved smile slipped onto the Asgardian's face as he heard the shuffle of covers, and then the tapping of bare feet on wood. "Thor?" He heard Loki's voice, muddled by sleep, but it was Loki's voice, and he hadn't heard it for a month. The door slid open, and - Thor had never seen his brother look so ill.

"'ki?" he frowned, staring at the younger man. He was bundled in sheets, hair a ruffled mess, skin six shades lighter than normal. When he embraced him, he found that he was cold, incredibly cold, and shaking. "Loki." he frowned, gripping his arms tightly. "Loki, what is the matter?"

Steve had been right. The god of mischief had lost weight. It wasn't like this hadn't happened before. Thor knew what ailed his younger brother. He'd just thought that it was over and done with. If he'd had any idea, he would never have left.

Loki hadn't had the best childhood. Incidents ranging from pregnancy to having his mouth sewn shut took place, and when he'd learned he had been adopted, memories either returned or formulated about being left alone in the cold. Those hurt the most, and Thor was painfully aware of it.

In the end, Loki was just scared, and alone, hurting more than he could explain. Hurting more than he could hide, although he was an excellent liar. Thor supposed that the pain he saw was just the tip of the very large - what was the word Natasha had used when she'd taken him to the museum about the iron-steam ship - iceberg.

In the end, though, it always came down to Thor to comfort him, and he did. It wasn't always easy, and it wasn't always quick, but if Thor was one thing, he was there for Loki. He was always there for Loki. He had made himself that promise when he thought he'd lost him for the first time, and he didn't mean to break it.