Johan Theory is a popular Swedish writer and journalist. At home, he is recognized as one of the best masters of modern detective fiction. His novels always feature a captivating plot, tension that never lets up until the very end, and breathtaking, stunningly beautiful Scandinavian landscapes, set on the Swedish island of Öland. The boy Jonas Kloss lives on the island with his aunt, uncle and older brothers. At night, he goes boating, and a terrible sight appears before his eyes. The impenetrable darkness suddenly thickened and took on the vague outline of a ship. The smoky silhouette was rapidly approaching and growing, Jonas did not have time to throw the boat aside. The ghost ship hung over the boy. There was no one on deck, only the quiet noise of an engine could be heard from somewhere, similar to the heartbeat of a huge beast... Thus begins the story of the ghost of an ancient mound.