Jean-Paul Sartre spent his life arguing that existence comes before essence, that no god or fixed human nature hands you a purpose, and that freedom is both a gift and a burden each person has to carry alone. This film traces his path from a bookish childhood and philosophy studies in Paris through his time as a prisoner of war, the writing of Being and Nothingness, and his emergence as the public face of existentialism in postwar France. It follows his partnership with Simone de Beauvoir, his involvement with Les Temps modernes, and his shifting politics, including his sympathies with Marxism and his refusal of the Nobel Prize in Literature. Archival photographs, footage of Sartre in cafes and at public appearances, and commentary situate his ideas against the backdrop of war, occupation, and the intellectual ferment of the Left Bank. The film treats his philosophy as something lived rather than merely written, tracking how his ideas about freedom and responsibility played out in his own choices.