Mysterier, known in English as Mysteries, centres on Johan Nilsen Nagel, an eccentric stranger who arrives in a quiet Norwegian coastal town one summer. His odd manners, sudden confessions and contradictory opinions puzzle and unsettle the townspeople. He becomes involved with a local clergyman's circle, a strange man called Minutten, and a young woman named Dagny. Hamsun leaves it unclear what is sincere and what is performance, making the novel a restless exploration of identity, sincerity and the hidden life of the mind.