The primary antagonist in the acclaimed British police procedural series Line of Duty was a shadowy and mysterious figure known predominantly as "H" or sometimes "the fourth man".
This enigmatic individual was established as the ultimate puppet master, heading up a powerful organised crime syndicate (OCG) that orchestrated a vast network of corruption. Operating from the shadows, "H" wielded significant control over various illicit activities, deeply embedding their influence within the system.
A key element of the show's enduring mystery and tension was the persistent suspicion that "H" might be operating from within the police force itself, possibly even within the very anti-corruption unit, AC-12, tasked with exposing them. The series revolved around AC-12's relentless pursuit to unmask "H" and dismantle the widespread corruption they represented, making "H" the central and overarching villain driving much of the narrative across multiple seasons.
