I'll Follow You
He knew he didn't have to come along, but he would never allow Merlin to go alone. Gwaine had known many people in his life, but few had made such an impression as Merlin had. There was something about the boy – an innocence mixed up with rebellion, some sort of confidence and loyalty, as well as good humor, that just attracted him far too much. He felt a pull towards him that wasn't at all sexual, as some might have though, but as a kindred spirit.
It had been easy to come back and help Arthur when he knew he could inspire the loyalty of someone like that. He hadn't even needed to think before embarking on a mad quest to the Perilous Lands, because while it might be dangerous, it would surely also be the trip of a life time. And meeting them in the middle of people ready to be sold as slaves, well, that was a tale to retell in every chance he got. Somehow, they had become friends – build a mutual trust even if they knew very little about each other. It wasn't easy to explain, even if one wanted to, but Gwaine never bothered much with that kind of thing.
From there, it had all just happened – the knighthood, invading Camelot, rebuilding everything, allowing it to become his home and his life. There was little time to muse over what was important, and very few things that might have torn him, until Gaius disappeared.
He worried for Merlin, even as the boy shunned him. He didn't need to be told that he was hurt, or that he didn't believe that Gaius had done nothing wrong. Gwaine thought that even Arthur didn't believe it much, but his actions spoke for themselves. He knew himself to be ready to accept another explanation, and if Merlin had one – if he needed help in anything – Gwaine knew where his duty was, even if those hadn't been the orders he received for the night.
There was little doubt as he went to Gaius' quarters, or as he offered his help. He didn't even mind when Merlin didn't seem to want anything but to be left alone, for he knew too well that it wasn't what he really needed. He stayed, and offered answers, and company, and anything and everything he could, as he knew Merlin would have done for him.
And if it meant an insane rush in the middle of the night, chasing something that they didn't even know what it was, so be it. He knew where his loyalties lay, and he would follow them to the end.