The 1970s is a decade known for its legendary cinema. Films like The Godfather, Dog Day Afternoon, Alien, Apocalypse Now, and One Flew Over the Cuckoo’s Nest cemented themselves in history during this time period, sparking the careers of directors like Martin Scorsese and Francis Ford Coppola and creating the “blockbuster” as we know it. But one revolutionary piece of cinema, just as compelling as any of those household names, is conspicuously missing from the usual lists of ’70s classics.

The Spook Who Sat by the Door, directed by Ivan Dixon in 1973, should be brought up every time someone speaks of the lasting impact of films from this era. Despite not being picked up by a major distributor, facing mountains of suppression from the FBI, and almost becoming completely lost before being converted to DVD, the film survived to become one of the most radical works in the history of Black cinema.

The Spook Who Sat by the Door is an adaptation of a 1969 novel by author Sam Greenlee. It follows the fictional story of the CIA’s first Black operative, Dan Freeman, who resigns from the agency and returns to his hometown of Chicago with a secret plan—to train members of his former gang in guerilla warfare in an attempt to start a revolution. The book was rejected 40 times by publishers between 1966 and 1969.