Nice thread names.
Personally, I think she would feel obligated to do it if she could help. How would she feel if she could have helped save someone's life and she didn't act? I think Lindsay is more of a scientist than a cop, as Eddie said in that interview recently, but she wouldn't hesitate to go undercover if the situation called for it. Of course, I also think she wouldn't volunteer unless she thought she could actually do some good--she wouldn't want to make things worse. And from what I've seen, Mac doesn't try to dissuade her, so you can tell it's a very serious situation if Mac wouldn't try to keep her from putting herself in harm's way...But I think Lindsay does it because she feels it's her duty, although I'd be interested to see if there's more that motivates her than just a feeling of obligation.