Line of Duty fans are already feeling anxious about Sunday's episode after it has been dubbed 'one of the best' from the series.
Martin Compston, who plays AC-12's Detective Inspector Steve Arnott, has said that episode four is a 'big one'.
Taking to Twitter, Compston said that it's some of writer Jed Mercurio's best work, with the potential of being a 'classic' in the history of TV dramas.
The actor also credits his co-stars for their performances in the 'midst of madness'.
He does a shoutout to Shalom Brune-Franklin, who plays AC-12's new team member Chloe Bishop, and Gregory Piper, who plays the undercover OCG member Ryan Pilkington.
Compston's tweet read: "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.
"Like to give a shout out to the young team Shalom and @gregorypiper98 who give outstanding performances in the midst of the madness".
The message, alongside a photo of DI Arnott pointing a gun, has received attention from fans, saying they're now left 'terrified'.
One replied: "well now I’m terrified, thanks Martin."
Another shared: "Mother of God, if it's more dramatic than the season three finale I might have to book myself a wee holiday from work for Monday."
A third posted: "I'm not sure I can cope... I feel an important death coming on... If it's Steve I'll cry for years!"
While the BBC cancelled its regular output on Friday in light of the Duke of Edinburgh's death, the broadcaster has started to announce their updated TV schedules for their channels.
Line of Duty is still set to air on Sunday, April 11 at 9pm.
