Bordeaux-based enologist (wine expert) Benjamin Lebel interrupts work on his next original wine publication, assisted by haughty relative and eager Virgile, to identify a Grand Cru château from Pomerol for police detective Barbaroux. It's used as signature in a ritual, filling one glass more each time, at a serial killer's successive murder scenes and a wartime tomb. Although told by the rude inspector to butt out, Lebel, who also receives anonymous, old pictures of the victims, works out they all had something to do with World War II, which the château vintage dates from too, and possibly with Vichy collaboration.