The film focuses on biographer Robert Caro and his editor, the documentarian's father Robert Gottlieb, as they work methodically to complete the final, fifth volume of Caro's Lyndon Johnson biography.

[3] The pair, both in their late 80s, had worked together for five decades, starting with Caro's biography of Robert Moses, The Power Broker, and continuing through Caro's first four volumes about Lyndon B. Johnson.

Its story is focused on the interplay between writer and editor as they work to finish the fifth book rather than a history of their lives.

At first, she only filmed them separately, at Caro's request, to avoid moments of contention.

[9] Metacritic, which uses a weighted average, assigned the film a score of 81 out of 100, based on 14 critics, indicating "universal acclaim".