substance. that doesn't sound like a highly weaponized thing. usually when it's weaponized, there are very small particles that can penetrate into the lungs, very different than what deb described. >> what happens when a particle goes into the lungs? >> well, this particular poison works at sort of what we call the cellular level, so the most basic level. the cells all over the body are constantly doing things, performing metabolic functions. ricin sort of interferes with that. it breaks down some of that machinery at its most basic level, and what happens if someone inhales it is that they will have difficulty breathing, some of the earlier symptoms. ultimately, their lungs will just start to fill with fluid in response to that poisonous insult. the lungs will try to respond, and that ultimately is what can cause death. >> if you know what you inhale, though, is it treatable? >> there is no particular