Line of Duty fans 'underwhelmed' as 'fourth man' is finally revealed - but viewers think there's another twist A long running storyline finally came to an end with the reveal of 'H' Updated The video will auto-play soon8Cancel Play now free email newsletterInvalid EmailSomething went wrong, please try again later. Subscribe When you subscribe we will use the information you provide to send you these newsletters. Your information will be used in accordance with ourPrivacy Notice. Thank you for subscribingWe have more newslettersShow meSee ourprivacy notice It was the finale millions had been waiting for as the sixth series of Line of Duty concluded in an explosive 60-minute episode on BBC One.