I have a terrible feeling that I just missed a link for this, or it's a super-classic and everyone will hate me for not knowing it. But I've been trying to find this fic where House and Wilson run into either an ex-patient or a deceased patient's family member, and he pulls a gun on them. House tries convincing him to shoot himself so he won't harm them, and I think it worked. I'm pretty sure it happened in a parking garage, but I'm not positive...I just remember it being absolutely fantastic. It was one of the first fics I ever read.