Oh, all viruses mutate. It's how they survive, just like anything else. [Fugo waves a hand, a little flippant.] But I don't think the Bristol virus is volatile enough to change that much this quickly. Maybe if humans were more resistant to it. It's an interesting process, but it takes time.

No, I think outside infected are getting inside the building. I don't know where and I don't know how, but it's the most reasonable way I can think of to explain their numbers.