With mechanical motion, Thor soaked the washcloth in the bowl of cool water, squeezed it out, and set it on Loki's forehead. Loki slept on, oblivious to Thor's tending. His breathing was raspy and his cheeks were flushed from a fever that refused to break. It had been three days since Loki had woken up last, and Thor counted those days among some of the longest he'd been through. If the fever didn't break soon there was a chance it never would, a chance that would just keep increasing.
Four days ago at breakfast Loki had told Thor that he hadn't felt so good and had gone back to his room to lie down. When he didn't show up for lunch, Thor had gone up to Loki's room to check on him. He had found his brother passed out on the floor, burning up from a fever.
Thor had carried Loki to the Healer's Ward, but the diagnosis was not clear. He was obviously sick. It wasn't a genetic virus or infectious; in fact, it didn't even look Asgardian in origin. When Loki had slipped into his current coma Thor had gotten permission to take Loki back to his room. Loki's room was saturated with his magic, and that might do something to bring him around. Thor hadn't left his side since, patiently spooning him a broth Fey had made to keep him from getting dehydrated as he slept.
Loki turned in his sleep, shivering from the chills he had. Thor fixed Loki's blanket and pulled it back up to his brother's chin. He rubbed his eyes, tired. Frigga had come in and relieved Thor a few times so he could nap, but Odin had yet to show up and check on his younger son.
If I was the one sick, Thor thought grimly, father wouldn't leave.
"No," Loki whispered, his features creased with pain.
He's having another nightmare Thor sighed.
"Loki," Thor whispered, leaning close. "Loki it's all right, you're fine, it's me Thor."
Suddenly Loki's eyes snapped open and he shoved Thor back. Thor, not at all expecting that, stumbled and fell.
He was on his feet in an instant. "Brother!"
Loki was breathing hard, emerald eyes clouded with fear. He looked at Thor and recognition replaced fear.
"Thor?" He whispered. "Is that you?"
"You bet," Thor moved the washcloth and sat down on Loki's bed. "Are you okay?"
"How long have you been here?" Loki asked, voice rough.
"A few days," Thor shrugged.
Loki beat sleep any day. Fey had said that since Loki was still a child his immune system should be able to shake off the sickness. She had been right.
Thor leaned over and felt Loki's forehead. "I think your fever just broke."
He grinned at Loki for a moment before remembering Fey's orders. Thor leaned over and picked up the bowl of broth. "Fey says that you're supposed to drink this, you'll be dehydrated."
Loki had read biology books so he didn't argue. His hands trembled as he tried to raise his hands to take the bowl. Thor shook his head and Loki lowered his hands, letting Thor lift the bowl to his lips. He only managed a few sips before he started coughing and Thor quickly lowered the bowl, setting it on the nightstand.
Loki glared at his hands He was so weak...
"You'll get stronger again," Thor promised. He was no telepath but he knew Loki well enough to read his emotions. "Your body used all its strength to fight off the virus. With that gone, it can focus on getting stronger. Besides, I'm here and I'm not going anywhere until your back to your old self."
"Promise?" Loki asked suddenly, surprising himself.
Thor was surprised to but he didn't miss a beat. "Of course, you're my little brother. I'll never let anything happen to you. I promise…"
That was the memory that flashed before Thor's eyes as he hung upside down on the end of the Bifrost he had just destroyed. All he could do was watch as Loki let go of Gungnir.
This is a flashback Thor has right at the end of the Thor (2011) Movie. Poor Thor promised and then this happens...
Some brothers tolerate each other, others hate each other, Thor and Loki were complete opposites and inseparable as children. Loki drifted away from Thor but Thor's loyalty to Loki never wavered. It hurt him a lot seeing Loki fall, realizing he had broken his promise.
The entire story is told from Thor's POV but there are only a few chapters and they're short. If you're new to my universe this is a good place to start, it gives you background that you need.
Thor, Loki, their parents, and Thor's friends are not the only beings in the nine realms in my fanfic so there are OC's coming up in later chapters.