Line of Duty star Martin Compston has suggested that the fourth episode of series six will rank among the show’s very best.
Episode four will air in the UK on BBC One later tonight (11 April).
On Twitter, Compston, who plays Steve Arnott, described the episode as “the big one”.
He wrote: “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.”
Shalom Brune-Franklin plays DC Chloe Bishop, who works alongside Arnott in AC-12, while Gregory Piper plays Ryan Pilkington, the crooked police rookie with ties to the Organised Crime Group (OCG).
You can find a breakdown of what happened in last week’s episode here.
Since the airing of episode three, a number of fans have spotted a clue which possibly links to the identity of “the fourth man” (formerly known as “H”), hidden in a kitchen tile in the background of a scene.
Some viewers also noticed a filming blunder during one scene featuring Compston, prompting a humorous response from the show’s official social media account.
Line of Duty continues on Sundays at 9pm on BBC One.
