AU where Dean and Cas are toddlers and Dean is scared of the dark based on this post by almaasi. I have absolutely no idea why Cas is part of their family, you can decide for yourself. [ao3]
Dean can’t remember his room ever being this Dark.
It’s not normal-dark like when his Mama flicks the switch after telling him his bedtime story or singing him a song, it’s the in-between of waiting for his eyes to magically make it lighter; when they’re almost there but can’t seem to reach that extra bit of brightness.