Au cœur du mensonge delves into the whys and wherefores of lying. Following the murder of a girl, an investigation begins. The first suspect is a slightly physically - and very emotionally - handicapped artist, Rene, who is married to Viviane (Sandrine Bonnaire). New to town, the couple have a hard time dealing with the suspicion swirling about them.

To combat her fears about her husband's possible guilt, Viviane allows herself to be seduced by a local celebrity, Demsot. Then a second murder is committed, and as a matter of course the town - and the main characters - are awash with lies.

According to Odile Barski, who co-scripted the film with Claude Chabrol, "the story is not intended as a justification of lying. Whether they are guilty or not, each character has his or her own lies as part of the scheme, participating in the hunt and running for shelters that are increasingly hard to find, and less and less safe." Nancy Tartaglione