Holy Hell! I just finished reading the most incredible story ever, and I have to rec it, because OMG!
It's
The Sea Will Rise by Exaggerated_Specificity.
It's a J2 AU, and it's amazing. Her writing is intense and her characters live and breathe. She doesn't pull her punches, and it was a white knuckle ride for me from start to finish.
Go read, and then tell the author how amazing it is.