Fans are loving the return of Line of Duty to our screens - but did you know that season one could have been very different? The show's creator, Jed Mercurio, has been rewatching the show with viewers, and has given some behind-the-scenes information about the making of the police procedural drama...
READ: Who is your favourite Line of Duty villain? Take our poll
Discussing episode three, which aired in early August, he tweeted: "Last night's episode featured the first-ever clandestine meeting between Steve and undercover Kate, filmed in Paradise Circus, Birmingham. Sharp-eyed viewers may have spotted that you never see their faces when they say 'Tony Gates.'
They had to change Tony's name halfway through filming
"That's because a couple of days into filming we had to change the name of @RealLennieJames' character. The actors re-voiced their lines in postproduction and we had to hide their mouths delivering the original name."
READ: Line of Duty fans on edge of their seats watching episode four cliffhanger
Although Jed didn't go into details about why the name was changed, one of his followers suggested that there was a very good reason. He wrote: "There was a police officer with that name. Since then all character names are checked with the Met to make sure no existing police officer has the same name."
Are you enjoying rewatching the show?
He also spoke about the final scene they shot, which took place in episode four, writing: "The scene featuring @RealLennieJames @Vicky_McClure in the pub was the last we shot. During the final take @martin_compston photo-bombed them and called 'Wrap'. That was the first time we heard his Scottish accent."
VOTE: Who is your favourite Line of Duty villain
Fans have been loving the anecdotes about filming, with one replying: "Thank you for all the great insights into this series. It was another amazing episode filled full of drama & all the hilarious #tedisms. It had me gripped right until the end, then the music kicks in.. Brilliantly done! Credit to you all."