As a bounty doctor, Dr. Rivers asks if it's appropriate to kill someone for a living. He's a doctor, after all, and he's got a lot of weapons to use against the guy. He wants to kill him, but he can't stand the thought of being killed by someone who doesn't even have a weapon to use at all. He tells the guy to stop bragging about how much he killed, and to give up on his new skills. He says he'll use his northern butterfly acupuncture skills to defeat the guy, but that's not going to work.