The passage between the World Above and the World Below was a simple affair; just a natural stone bridge at the mouth of the cave entrance. Not that anyone (or, indeed, anything) had passed through in as long as anyone could remember.

This must be the river of life, Maria thought. As if to confirm, the glow coming from the bottom of the ravine seemed to pulse, making her lamp look sadly inadequate even though it had guided her way through the miles of forest she’d crossed to this point. It was said that if one looked at the river too long, one’s…