Line of Duty: Unpacking the clues around James Nesbitt's character Marcus Thurwell The Northern Ireland actor made a surprise cameo appearance in the show The video will auto-play soon8Cancel Play now Never miss a thing from Belfast and beyond - sign up for FREE newsletter direct to your inboxInvalid 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 Northern Irish acting legend Jimmy Nesbitt found himself with a cameo role on Sunday night's episode of Line of Duty, sending viewers into a frenzy.