Set in 1917, Le Matelot 512 unfolds within the rigid hierarchy of the French Navy. The film follows Max, a young sailor identified only by his service number, emphasizing the loss of individual identity in military institutions. Stationed at a naval base, he lives under strict discipline and routine. After a minor, ambiguous incident, he is accused of desertion and insubordination and placed under arrest. Rather than a dramatic trial, the film depicts a slow, impersonal process of interrogations, confinement, and bureaucratic inertia. As time passes, the sailor emerges as a scapegoat, sacrificed to uphold authority during wartime. Isolated and forgotten, he endures waiting as a form of punishment, revealing the quiet violence of institutional justice.