William Somerset is a seasoned homicide detective, enveloped in a pervasive melancholy that emanates from both his conscious and subconscious awareness of humanity's capacity for evil. As he approaches retirement, Somerset is burdened by the weight of nearly four decades spent witnessing the worst that society has to offer. Deep inside, he is a reflective existentialist, wrestling with philosophical dilemmas about good and evil while remaining committed to his duty of hunting down a serial killer whose grisly murders revolve around the seven deadly sins.
This relentless pursuit not only forces him to navigate a sordid urban landscape riddled with despair, but also challenges his own moral beliefs and dictates the course of his interactions with his more impulsive younger partner, Detective David Mills. The juxtaposition of Somerset's cynicism and introspection against Mills' exuberance highlights their respective worlds—one shaped by experience and loss, the other by ambition and hope. In this process, Somerset's complexity unfolds, revealing a character who yearns for understanding and connection within a milieu of chaos and despair.