On a summer night, police recover the body of a young woman from a pleasure boat drifting around the Stockholm archipelago. The forensics team is sure she drowned. But the boat was afloat, with no trace of water on her body. The next day a man turns up dead in his apartment, hanging from a high lamp hook, with nothing near him to climb on. Joona Linna begins to piece together the two mysteries, but the logistics are a mere prelude to danger.