The first series of the gritty detective drama last year saw the audience discover DCI Tom Brannick’s shocking secret while the characters were left in the dark.
Brannick was revealed to be notorious assassin Goliath, a secret he killed to protect.
With the second series due to hit television screens on Sunday, Nesbitt said that while the audience is one step ahead, they do not know what he will do next.
“So much has happened in the world since Bloodlands, and so I think this one is definitely breathing more, and I think the storyline is very interesting – the audience knows something that no one else does,” he said.
“That gives you a really interesting platform to see how the chinks in his facade begin to happen, the audience is one step ahead but they don’t know what Tom is about to do.
“He’s a policeman who is a murderer, a liar but someone who, I think, you are intrigued by, you can also see the human side to him, the relationship with his daughter, the pain that he has felt in his life, the disappearance of his wife.”
The new series sees the arrival of Nesbitts’ former Cold Feet co-star Victoria Smurfit as Olivia, an enigmatic widow at the centre of Brannick’s latest case.
Smurfit described her character as “intriguing”.
“At the top of the show she’s dealing with the murder of her husband. There’s a lot to her, she’s complicated, she’s instinctual, she’s driven… and I love her,” she said.
“She’s a really, really interesting woman to play. Just when you think you know what she’s thinking, you don’t.”
Smurfit said filming in Northern Ireland was fun, picking out Tayto crisps and friendliness as highlights.
“It’s just so lovely. I’d work here again in a heartbeat.
“Watching the crews work here in Northern Ireland is sort of like watching a Chinese dragon, everybody is moving and undulating around the set.
“The community of the different departments of the crew is just astonishing. There’s no shouting or roaring, it’s just a joy to watch.”
Charlene McKenna is returning as DS Niamh McGovern, and teased that the second series is even better than the first.
“I think it’s really good… you never want to say that because you never want to jinx anything, but it’s really strong,” she said, adding that she enjoys the fact that the audience now knows about Brannick’s secret identity, but the rest of the characters do not.”
“It’s nice, you guys knowing, and us sniffing, and the introduction of Smurfit’s character adds a really, really gritty and antagonistic element.”
She described her character as the “conscience of the piece”.
“I feel like she is saying what the audience want to say to him, I do think Niamh is a good egg… but she’s getting pushed, she is getting more cornered, which I think is a lovely problem to put her in.
“I think people resonate with her, and they want her to get him, to crack it.”
Writer Chris Brandon, originally from Northern Ireland, admitted he had written Bloodlands as a spec script, adding: “I never thought anyone would make it.”
He said Line Of Duty producer Jed Mercurio was the first to say “we can do this”, while others were daunted by the idea of filming in Northern Ireland.
He described his inspiration as the Strangford Lough area where he grew up, and Scandinavian thrillers.
“I was led first by atmosphere and character, I was always interested in that idea of a policeman who faces that struggle between justice and keeping the peace, and when those two things can’t necessarily live side by side, then what does he choose,” he said.
He said some people on the crew had known him since he was a baby.
“There is an immediate comfort to that and and an immediate familiarity, and even yesterday I was walking down the lough, thinking I had done this so many times in my life, but to be back here doing it professionally, it’s that sort of meant-to-be thing, crazy,” he said.
Asked whether there is likely to be a third series, Bryant said: “I think we always hope for more,” adding: “Brannick is a character that can give us, and is going to give us, so much excitement, so I think we’ll get to the end and see what people think.”
Series two of Bloodlands will start at 9.05pm on Sunday on BBC One.