When you get sick, it starts off with a single infection. One lone nasty intruder. Pretty soon the intruder duplicates. Becomes two. Then those two become four. And those four become eight. Then, before your body knows it, it's under attack. It's an invasion. The question for a doctor is, once the invaders have landed, once they've taken over your body, how the hell do you get rid of them?
Meredith (narrating)
