" It is said, once a wise man from the far North told me; it is said that there are in certain parts of Scandinavia cities within cities like there are circles within circles; existent yet invisible. And those cities are inhabited by creatures more terrible than imagination can create : man-shaped but man-devouring, as black and as silent as the night they prowl in. "

― Johanna Sinisalo , Troll: A Love Story