A man enters the bank with something resembling a bomb around his neck. He demands that money is transferred into an account, or he will blow up the bank. The man is known as the village idiot, and claims that Sitting Bull is his father. No one take the case to seriously until they find that the bomb is real. Is the village idiot acting on his own, or are there more people involved? A long and complicated investigation is started by Kurt Wallander and his colleagues.

The Ystad Police finds a boat in Ystad harbour resembling a slaughter house. There is blood everywhere, but no bodies.

Soon there after a dead woman’s body floats ashore. One of the clues in the investigation leads to Oskar Ung, an old love of Linda Wallander. Their previous relationship hinders Linda's work with the case, and Kurt demands that she leaves the investigation But that turns out to be easier said than done. Old love never rusts.