i remember reading it once and then finding it on here again but i totally forgot to bookmark the story.  i remember it was a group of ex-militants (3 or 4) and they kidnapped dean to replace one of their number.  they kept his water drugged. and they were out on a ranch or something out west.  and there was a sequel, where sam and bobby caught up with him but dean wouldn't leave cause they had something over him. 

sorry, that's all i remember. please help! Thanks in advance!