The setting is Paris in the spring of 1968, amidst student protests. "Matthew," portrayed by Michael Pitt, arrives from America and connects with the brother-and-sister pair, “Theo” (Louis Garrel) and “Isabelle” (Eva Green), who share his passion for movies. They extend an invitation to their house for dinner while their parents are away. It quickly becomes apparent that these two siblings have a peculiar closeness—n…