To really, really pinpoint where it started, the flowers turned superactive. They took the sniffing dogs with them, the sniffing dogs infected their masters.
As each of these things started to meld with one another, creating hybrid creatures that were insane from birth, no one managed to see them, except for one girl. She was the kind of person who was really prepared for invasions, the kind who knew how to weaponise at least twenty ordinary objects in her environment, the kind who, if you asked her, could tell you five ways of holding off a horde of werewolves.
She went home and began preparations. The house became a fortress. Every implement that couldn’t be used to cook was sacrificed for the defence. Locations for scavenging were marked on a map. And now, every evening, she sallies forth to fight the doom nobody has noticed.
Out of context, she’s someone who has souped up a toaster into a weapon and kills people with it. Which is why you need context, right?