Anna, a writer, draws inspiration for her fictional characters from people around her on the island of Mallorca. She meets Nils, a Danish man living in a cave-house. Their relationship develops, but Nils is a man with a lifetime of secrets. Why is he shadowed by a primeval Norse dragon, which visits Anna in dreams? When Anna's employer falls from his penthouse roof terrace, it sparks a trail of clues, as Anna and her friends Maggie, Jane, and Zhu try to discover what Nils is hiding behind a locked door in the cave-house, and what happened to his former wife?.