Magic takes several forms in my book. Without getting spoilery: The characters in my story have no idea what magic is or is not, readers will have to discover that along with them. I can say that much of what they encounter first will be dark and frightening. There is more to what is happening than they will know, but I’ll leave those surprises for readers to work out for themselves.
In my story magic doesn’t appear full blown after a long absence, but builds over time like water flowing into an empty vessel. That makes magic weak at first, and keeps many magic creatures that might wander into the world away. An exception to this are creatures from the Dark Domain of the Dead. Since they are already dead, Earth’s environment poses no challenge to them. The first, most obvious danger in the story comes from mindless, animalistic zombies, animated corpses only intent on eating the flesh of the living, and spreading their undead taint among an unprepared world.
Fortunately for the world of Fantastic America, people don’t remain unready for long. Imagine the chaos of actual zombie outbreaks, and how modern epidemiologists would respond. Still, ravenous undead remain a looming threat in the steady march to awareness of just how much the world has already changed, and a foreshadowing of home much change is yet to come!