He woke up to the sounds of his baby brother crying and padded softly out of his bed and across the room to where Gray's bed was and sat cross legged next to the boy's head and shook his shoulder to alert him of his presence. "Why are you crying?" he asked Gray.
"Bad dream." The younger snuffled miserably. "Lots of monsters came, and Dad told you to run and keep me safe and you did and we were running fast but I couldn't run fast enough and you let go of my hand and the monsters got me."
"Well that was obviously not true then, weren't it? I'm here, you're here, the only monsters are when Mum and Dad get angry and shout at us for trying to make snow, and they aren't monsters really because they're Mum and Dad."
"I guess," Gray agreed as he tried to follow his brother's quicksilver logic. "Thank you, Blue," he told his older brother, using the name that everybody on the peninsula told the young brunette in reference to his sapphire blue eyes. Only their parents had ever called him by his real name once when they told them off for trying to make snow.
"Hey, it's what big brothers are meant to do, right?" Blue asked him cheerfully. "And even if some monsters did come and Dad told me to keep you safe, I'd make sure I'd never ever let go of your hand. I swear on Mr Smokey." He nodded towards where his favourite teddy bear sat lopsidedly on his pillow. "And if the monsters did take you, then I would join the time agency and learn to travel in time so I could get you back."
Just then they heard their mum calling for them to come down for breakfast, and they happily ran down the stairs, the nightmare all but forgotten.
So when the monsters did come and take Gray 7 years later, Blue did join the time agency, and although he couldn't just go back to that day and save his brother, he never stopped looking for him.
And even when, however many years later, Gray killed Tosh, he knew he didn't truly hate his brother because he remembered the promise the person that used to be Blue had made to him, and he knew he would have honoured it if he could because his brother had never let him down.