The film features many interviews with French communist leaders, students, and sociologists. The Prague Spring of 1968 is featured, with footage of a Fidel Castro speech in which he explains his political support for the Soviet invasion of Czechoslovakia while questioning the legality of the action. Other sections deal with the rise of Salvador Allende, Minamata poisoning in Japan, and the Watergate Scandal in the US. There are many subtle references to cats throughout the film, as well as brief shots of raccoons.
A Grin Without a Cat is a 1977 French essay film by Chris Marker. It focuses on global political turmoil in the 1960s and '70s, particularly the rise of the New Left in France and the development of socialist movements in Latin America. Using the image of Lewis Carroll's Cheshire Cat, the film's title evokes a dissonance between the promise of a global socialist revolution (the grin) with its actual nonexistence. 
The film's original French title is Le fond de l'air est rouge, which means "The essence of the air is red", and has a subtext similar to the English title, implying that the socialist movement existed only in the air