Karin Fossum (née Mathisen) is a Norwegian author of crime fiction,often known there as the "Norwegian queen of crime". She lives in Oslo. Fossum was initially a poet, with her first collection published in 1974 when she was just 20. It won the Tarjei Vesaas' Debutant Prize. She is the author of the internationally successful Inspector Konrad Sejer series of crime novels, which have been translated into over 16 languages. She won the Glass key award for her novel "Don't Look Back", which also won the Riverton Prize, and she was shortlisted for the Crime Writers' Association Gold Dagger in 2005 for "Calling Out For You".
Early one September three friends spend the weekend at a remote cabin by Dead Water Lake. With only a pale moon to light their way, they row across the water in the middle of the night. But only two of them return, and they make a pact not to call for help until the following morning.
Inspector Sejer leads the investigation when the body is discovered. He is troubled by the apparent suicide and has an overwhelming sense that the surviving pair has something to hide. Weeks pass without further clues, and then in a nearby lake the body of a teenage boy floats to the surface.