There was very little text and mostly illustrations. The story involved a girl whose lover(?) is taken away by a witch. She goes to the witch’s lair and there are many birdcages with owls in them. Her lover(?) is also being kept in a birdcage when she saves him.
The pictures had a very dark colour scheme with a gothic/art nouveau art style, similar to Kay Nielsen but darker. I remember being fascinated with this book as a child as the content was so dark compared to my other books. I’ve been trying to locate it for years but cannot remember even slightly what the title was.
If it helps, I suspect the author was European given the content, so the original book was probably published in Finnish, Danish or German.