She is about to become immersed in a mysterious labyrinth of betrayal, complicity and dark secrets. A stylish Parisian thriller, “The Art Dealer” is set in the murky world of Nazi-looted art. Directed by the renowned François Margolin (“The Flight of the Red Balloon”), it begins when a Jewish woman investigates stolen family paintings only to uncover a story that has been carefully buried for decades by those closest to her.