A body is found at an ATM, the apparent victim a of heart attack. Then, two teenage girls are arrested for the brutal murder of a cab driver. The girls confess to the crime, showing no remorse whatsoever. Two open-and-shut cases.

At first these two incidents seem to have nothing in common, but as Wallander delves deeper into the mystery of why the girls murdered the cab driver, he begins to unravel a plot much more complicated than he initially suspected. The two cases become one and lead to a conspiracy that stretches far beyond the borders of Sweden.