The Line of Duty ending was perfect – you just don’t know it yet Convinced that Jed Mercurio’s finale wasn’t explosive enough, or that H was too banal? Then you just haven't been paying attention One of the few action-packed scenes in Sunday's divisive finale of Line of Duty Credit: BBC Here’s an alternative scenario. We watch a grey-jumpered figure being led into AC-12’s infamous “glass box” interrogation room. This is him, this is H. The camera lingers on the suspect’s back before cutting to the doleful gazes of our three AC-12 heroes. The interview begins. The camera cuts to the face of our suspect – Chief Constable Philip Osborne.