I think this is one of Henning Mankell's best crime novels. Four nuns and a fifth woman are murdered in an unnamed African country, and there is an attempt at a cover-up, which is torn open by a police officer with a conscience.

The killing sparks off a chain of murders in Sweden, which are investigated by Inspector Kurt Wallander and his team, and as their investigation proceeds they find that they are also investigating crimes that have apparently been committed by some of the victims.

To say much more than this would probably reveal too much of the plot.