Genres
Noir
Protagonist trapped in a corrupt system, distinct from the tough-but-moral hardboiled detective.
Noir fiction is frequently conflated with hardboiled detective fiction through film adaptations, but the formal distinction holds: in hardboiled, the protagonist is a tough, morally compromised private detective who nonetheless serves the truth; in noir, the protagonist is a victim, suspect or perpetrator trapped in a corrupt system. The noir hero does not solve the system; the system digests them.
The distinction matters for series continuity: hardboiled builds a recurring detective with a stable cast, noir builds tighter single spirals.