The 'Line of Duty' cast will be start shooting series five in the autumn of this year.
Adrian Dunbar in Line of Duty
Adrian Dunbar - who plays Superintendent Ted Hastings in the drama - has confirmed him and his co-stars will start filming the new instalment later this year, but he has admitted he doesn't know what happens to his alter ego because he hasn't received the script from creator and writer Jed Mercurio yet - although he knows it'll be "dark."
Speaking to the Radio Times magazine, he said: "I haven't seen anything, Jed hasn't told us anything. We're all keeping our fingers crossed that we're not bumped off.
"We'll be shooting the next series at the end of this year, some time in the autumn, so sadly we'll all have to wait until 2019 to find out what happens to us all."
Jed has worked on the drama - based on the investigations of AC-12, a controversial police anti-corruption unit - scripts for the last six years and has teased he has some exciting things up his sleeve for the future that he thinks will keep viewers hooked.
He said last year: "Yeah. That's an area of interest and will be explored. The fact is that 'Line of Duty' has a very big story arc across all the series and one of the things that we haven't done is to delve into Hasting's past. That will happen in a future series."
As head of the police unit, Hastings stands accused of discriminatory management and unethical behaviour, and his back story is going to be explored in more depth.
However, although he has everything set out in his mind, Jed has admitted he's not afraid to go back to the drawing board when something unexpected happens.
He said: "Even though Adrian didn't fit the character I'd sketched, he did something very vivid and interesting with the lines, and so I reconceived the character to fit him. I regard that as one of my great pieces of luck, to the extent that I now see auditions as being part of the writing process."