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"the spook who sat by the door" This phrase is famously known as the title of a novel:

The Spook Who Sat by the Door

• Author: Sam Greenlee

• Published: 1969

• Genre: Political thriller, African-American literature

• Plot Summary:
  The story follows Dan Freeman, the first Black CIA officer, who uses his training to organize a Black guerrilla movement in the United States. The novel explores themes of racial inequality, espionage, and revolutionary activism.

• Cultural Impact:
  The book was adapted into a film in 1973, which became a cult classic. It is considered an important work in African-American literature and political commentary.

If you want, I can provide more details about the book, its themes, or its historical context!