The mystery of the lost Cézanne

Antoine and Marine are investigating both a murder and the provenance of a mysterious painting. Could it be a genuine Cezanne? Pierre, a friend from Antoine Verlaque's cigar club asks him to visit a cranky old man named Rene, who thinks he may have discovered a Cezanne painting. But when they arrive, Rene is dead, the painting is gone and a beautiful American art history professor is in Rene's flat. Did she kill Rene? And where is the painting?