An old eccentric living near the French border threatens a housing inspector with his two-barreled gun. Chantal believes the man should be helped, rather than prosecuted. But then a body is found on his property.

Now that the blackmailer is known, a major operation is set up to ensnare him. A great responsibility for Chantal who wants to prove with this operation that she can handle these kinds of situations just as well or perhaps even better than D'Haese and Co.