Who are you in this story? If you're the Girl... God chose you to save the world. Congrats. Here's the thing: Nobody gave you any superpowers. You get no Slayer strength, no kung-fu grip, no costume. You're just you. Except, of course, for the Super 3-D Saint John of Patmos Vision<small><sup>TM</sup></small> where you pass someone in the street and you see the numbers on their forehead, or a lamb standing as if slain, or that goddamned dragon again, and you know what their destiny will be. If you don't change them. Convert them? Seduce them? Shoot them in the head? That's up to you.
Engines are enduring features of the world that drive the story -- until someone destroys them, of course. An Engine gives the player who controls it dice to roll, every turn. These dice are stacked in a Ready Pile next to the card until you use them. An Engine can be anything: a person; a personality trait; a temptation; a danger; an object; a place; an idea.