Martin Compston has ramped up excitement for episode 4 (Picture: BBC/World Productions)
So far in series six of the procedural, Kate Fleming (Vicky McClure) and her former AC-12 coworker Steve Arnott (Compston) have been trying to get to the bottom of the murder of journalist Gail Vella (Andi Osho) while also figuring out how corrupt police officers could be involved in her death.
In episode three, viewers were aghast as they witnessed police officer Ryan Pilkington (Gregory Piper) murder his colleague Lisa Patel (Tara Divina) by drowning her before pretending to save Terry Boyle (Tommy Jessop) when Kate arrived on the scene.
In a tweet shared ahead of the new episode on Sunday, Martin told his Twitter followers that they have a great deal to look forward to in an instalment that he reckons could be deemed ‘a classic’.
‘Tomorrow’s the big one episode 4! On paper one of the best @jed_mercurio has ever written, if we deliver what was there potential to be a classic,’ he wrote.
Martin also took the opportunity to commend Shalom Brune-Franklin and Gregory for their impressive performances as Chloe Bishop and Ryan respectively.
‘Like to give a shout out to the young team Shalom and @gregorypiper98 who give outstanding performances in the midst of the madness,’ he said.
Gregory replied underneath the tweet, stating: ‘Big love man! Can’t wait for tomorrow, you’re smashing it!’
The picture in Martin’s tweet showed Steve pointing his gun upwards, a steely expression on his face.
So despite Steve’s severe back pain, it appears the character is going to get involved in some heavy action in the new episode.
Martin praised Shalom Brune-Franklin’s performance as DC Chloe Bishop (Picture: BBC/World Productions/Steffan Hill)
Will Gregory Piper’s Ryan Pilkington be found out? (Picture: BBC Pictures Archive)
Several fans expressed their excitement over Martin’s big claims about the upcoming episode.
‘I can’t wait I just hope nothing too bad happens to our Steve Arnott don’t think I could cope if it does,’ one person commented.
‘Well @martin_compston I was beyond excited already & now you’ve whipped us all into a frenzied excitement!!’ another replied.
Someone else remarked: ‘I bet the whole team knock it out of the ball park. This series has been amazing!! Bring it on!’
Could episode four see Ryan get his comeuppance after seemingly getting away with the murder of police officer Lisa?
And will Joanne Davidson (Kelly Macdonald) continue to arouse the suspicion of AC-12 boss Ted Hastings (Adrian Dunbar)?
Line of Duty airs on Sunday at 9pm on BBC One.