Spirits in Fylgja are not metaphor. They are real, dangerous, and everywhere. People speak to them, sacrifice to them, fear them.
Every person has a guardian spirit. Every family has ancestor spirits. Every grove, river, and mountain has its own land-spirits. The dead do not always stay dead. And the Norns spin fate for gods and men alike.
These are the powers that share the world with humans — and they are not always kind.