Line Of Duty's Jed Mercurio reveals storylines can change depending on the stars' schedules

Jed Mercurio has said that he tries to keep things flexible when writing Line Of Duty and waits until a new season is coming together to start casting. Sketchy: He detailed how he dropped a sign the officer was bent back in 2012 after he allowed Dot Cottan to speak with Tommy Hunter alone Corrupt: At the end of series one Cottan and Hunter are seen talking alone, with the officer telling the criminal to play along with the investigation to get immunity Jed continued that Buckells being seen as a bit useless and bumbling ended up being written into the script to the officer's advantage. Back at the start: The 2021 series of Line Of Duty saw AC-12 investigate DCI Tony Gates and Jackie Laverty is also introduced Storyline: A series 4 return saw him involved in the storyline starring Thandiwe Newton as Roz Huntley as main corrupt officer And as H was finally revealed on Sunday night's long-awaited Line Of Duty finale, many shocked fans realised they'd been looking at the mastermind the entire time. A reveal: The biggest giveaway for Buckells turned out to be the word 'definately', with his repeated spelling gaffe turning fingers his way Line Of Duty finale: How the viewing figures compare 2021 Line Of Duty finale, May 2 12.8 million Prince Philip's funeral, April 17 13.6 million Harry and Meghan with Oprah Winfrey, March 8 11.7 million 2020 Boris Johnson lockdown announcement, March 23 14.5 million Queen's address to the nation, April 5 14 million Boris Johnson's second address to the nation, May 10 18.7 million I'm A Celebrity Get Me Out Of Here!, November 15 12.1 million 2019 Gavin And Stacey Christmas special 17.1 million viewers 2012 Closing ceremony of the London 2012 Olympic Games 24.5 million 2010 The X Factor 17.7 million 1995 Princess Diana interview with Martin Bashir 23 million 1966 The 1966 World Cup final 32.3 million viewers A hole in one Earlier in the series, viewers saw a set of golf clubs in Hillsgate police station and noted that the clubs have strong significance. Describing the ultimate villain, Nigel said: 'He's very competent, very good at what he does, he's the go-to guy, but he's certainly not a popular guy' Man down: Pilkington was killed after confessing to multiple murders on the show, yet some eagle-eyed fans realised it was clear Buckells must have been aware of his real identity from the start Buckells hired 'baddie' Ryan Pilkington Pilkington was killed after confessing to multiple murders on the show and met a sticky end at the hands of Kate Fleming in a fierce shoot-out.