At the Café René in the small French commune of Nouvion everything is as usual. Chaos. René himself is trying to keep a straight face in a dangerous game. Of course he has to stay on the good side of the Germans in order to not get in trouble. He also has to do the same thing with his wife Edith for the same reason. For completely different reasons he stays on the good side of his waitresses Mimi and Yvette. At least when Edith isn't around.

About Vipeholmsanstalten in Lund, Sweden, and the experiments that during the 40s and 50s were carried out on mentally and physically handicapped patients, to investigate the effect of sugar on the teeth, this at a time when tooth decay was a major problem in dental health in Sweden. By force-feeding the patients at Vipeholm a kind of extra-sweet caramel in large quantities, the experiments revolutionized research, while the defenseless patients had to take the hit for it.

When an arsonist is released from prison, the villagers do not want him anywhere near them. Soon they take matters into their hands and Wallander has to investigate whether their fear is justified.

A strange old man moves in to the abandoned apartment next to Sara's. We soon realize that his intentions are devious. Someone is in trouble, something bad is going to happen. But things may not be exactly as they seem.