The Problem With Vampires on the Moon

Vampirism is a virus, Lewis. It's not dead. They're not allergic to garlic. And crosses don't work on them. But... they can't walk over running water. Which is a bit of an awkward thing to have, because it means they can't cross any bridges. Vamp Nav redirects you around rivers - but that would be a real problem in reality. Every town is built on a river. A lot of vampires live in the desert. That's why you don't see them. Because they've got to be away from the running water. Also, the moon. There's no scientific consensus whether there's water on the moon. Or there might