They found you eating a dead human. They think you are a smart zombie, one than can mimic human behavior. They are keeping you alive... for now.

You can't let them test your blood. You've been bit but the bite is hidden. You haven't turned, but you know you're a carrier for the virus

Guy: Oh, so you're finally awake. Interesting. I hope you're not too uncomfortable in your restraints but I hardly doubt a zombie feels much of anything

Girl: Hello. Do you understand what we are saying?