Line of Duty's Martin Compston has hinted tonight's episode will be 'one of the best' in the series.
The actor, who plays Detective Inspector Steve Arnott, left fans on edge as he tweeted to say episode four will be a 'big one'.
Mr Compston said he believed it was one of the best instalments Jed Mercurio has ever written, saying it had the potential to be a classic.
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While hinting about the episode's 'madness', the actor also credited his co-stars for their incredible performances.
He gave 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, reports the M.E.N.
Mr 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.
