Get Carter (1971)

Jack Carter, a London enforcer navigating the city's underbelly, receives news that shatters his carefully constructed world: his brother is dead. Drawn back to his hometown of Newcastle for the funeral, Carter confronts a past he thought he had left behind. Rejecting the official verdict of suicide, he descends into a labyrinthine investigation, seeking the truth behind his brother's demise. Each encounter, each shadowy figure from his brother's life, pulls him deeper into a conspiracy of violence and betrayal, revealing the dark secrets that fester beneath the surface of the city. Vengeance becomes his sole purpose as he unravels the mystery.