If you look at the original lj fic post, there are 18 pages of comments so far. It is that amazing.
It goes beyond pairings and characters. It's history and life and Atlantis. Damn it - I think I have a crush on cesperanza now.
Notice: Actually, even if you've never seen SGA, approach this fic as an original fic. Or hell, wiki SGA and read the character profiles and then read it. Don't let fandom differences sway you, 'cause brilliant fic is brilliant fic. I just stayed up all night reading this. I can't even put my emotions into words. Bloody hell. It a fic that can make you fall in love with a fandom.
Child of ETA: Y'know, I'm reading all the posts reccing this fic (on technorati) and in the past 6 days since the fic hit the internet there's been this rippling shockwave as a whole fandom stops and kinds of just FLAILS WITH LOVE. It is fabulous.
Grandchild of ETA (y'all knew it was coming): Favorite recs of this fic are here, here and here.