On a warm August evening, a stranger approaches Carol and asks for her help — but refuses to say who he is. She declines. The next morning, his body is pulled from the Norrköping River. Carol decides to find out why the dead man wanted to hire her. The trail leads into Swedish political history and eventually to connections with the murder of Prime Minister Olof Palme. What starts as a question becomes a situation that puts Carol herself in serious danger.