I suppose most science types have heard of Schrödinger's experiment with the cat. Quantum physics, superposition of states, and stuff.
You put a cat in a box that is completely sealed against observation, along with a device that has a 50-50 chance of breaking a vial of poison. Because you're not observing it, its state doesn't collapse to either alive or dead; instead it ends up being both alive and dead!
Anyway, enough backstory. One night I was feeling a bit bored, and being a science geek (and more than a little eccentric) I decided to give it a go.
The device was surprisingly easy. Finding the cat was easy too - my tortoiseshell Ngeru; I'm a cat person, but science comes first. The tricky part was making the box tight enough to completely isolate its contents.
I suppose I only guessed what had happened after 'the incident' with the neighbour's toddler. When I let Ngeru out of the box after the requisite one hour, she looked a bit odd; but I put that down to resentment for the attempt on her life. I'd accounted for her being peeved and taken precautions, so I escaped immediate harm.
Over the next several days the neighbours' cats and other domestic animals started behaving strangely, and a lot of those that I saw had that same odd look Ngeru had.
As I said, after 'the incident', it came to me... the whole superposition thing. Being both alive and dead, or neither, however you want to describe it. That's pretty much the definition of being undead!
I suppose it took me so long to piece together and noone believed me because, for a cat, the only unusual part of being an evil undead creature of the night, is the undead bit. And I'm sure it must be hard for people to tell their kid "I'm sorry Bobby, but Mister Meowington has turned into an undead monster that wants to eat your face, or suck your blood, or pretend your kidneys are a yarn ball."
So now my suburb has fallen, and I'm holed up in the basement. I heard civil defense sirens, maybe they'll be able to contain them.
Now I'm all alone down here. Isolated.
I hope I stored that device safely.