Gashiyeon: Thorn Lily/Thorn Year, a fanfiction written by Maio. The series is divided into 3 parts - Reduced Horizon, Thorn Lily, then The Fox's Cradle. It's an extremely dark, but stunningly beautiful and profound piece of work. Explicit homosexual content so please read at your own risk.
I'm surprised Jaejoong could still bring himself to look at Yunho after reading this ^^; Maybe Yunjae is real after all? (Delusions of a fangirl)