I'm writing to let you know that I have now quarantined myself. So you and I both know this is going to end one of two ways. You win, and I die. Since you need me alive, this would end very badly for you. My immune system kills you. Due to the aforementioned quarantine procedure, I can guarantee that this will happen before you have been able to transmit yourself to any additional hosts. I'm willing to make a deal. Leave now, and I'll order my white cells to stand down. But continue, and I guarantee that you will be annihilated in the most unpleasant way possible. (Or we both die). Your move. TL;DR: I'm ill. Sympathy me.