'Everyone has an opinion about Colin'

THE Secret, a new ITV drama starring James Nesbitt, might be set in Northern Ireland in the early-1990s, but it's not dealing with the typical subject matter. In fact, as Ballymena-born Nesbitt notes: "It's quite interesting to go home and do something that isn't about the Troubles."

The four-part series – directed by Nick Murphy, who previously worked with Nesbitt on 2009's Occupation – instead details the true story of dentist Colin Howell (Nesbitt) and Sunday school teacher Hazel Buchanan (Genevieve O'Reilly). They embarked on a passionate affair after meeting at their local Baptist church in Coleraine, the town Nesbitt grew up in, which had catastrophic consequences, resulting in the deaths of Colin's wife Lesley, a former nurse, and Hazel's husband Trevor, a police officer.

At the time, it appeared they'd taken their own lives in a suicide pact. It was only years later that Colin (he and Hazel eventually split and both remarried) confessed to the murders, further shocking the close-knit community.

"My sister used to go to Lesley's coffee mornings and two of my best friends were patients of Colin's," reveals 51-year-old Nesbitt, who recalls a scene in which Colin runs past his parents' house after the killings.

"To see that is quite chilling," he adds. "For all intents and purposes, this was a community that was law-abiding and well-respected. It's quite easy to imagine that Baptist community as an odd and cultish world, but it wasn't at all. They're certainly a close community, but I knew a lot of these people, and they're charitable people that will go out of their way to help you. It was interesting to be given an opportunity to explore the dark side and, indeed, see how wickedness and evil can flourish under the cover of religion."

The drama traces the pair's initial meeting, affair and how they carried out Colin's plan to kill Lesley and Trevor, through to the inquest, Colin's confession and the subsequent murder trial. Hazel admitted involvement but pleaded not guilty, claiming she was coerced.

"Everyone now has an opinion on Colin, particularly in Northern Ireland, where there's almost a frenzy about this [the series] coming out," continues Nesbitt, who has two daughters with wife Sonia Forbes-Adam. A lot of people would say, 'Oh yes, I knew there was something strange about him', but that's in retrospect, and the retrospect is influenced by the fact he was convicted."

In preparation for the part, Nesbitt spoke to veteran reporter Deric Henderson, former Ireland Editor of the Press Association who wrote Let This Be Our Secret, on which the drama's based.

"I knew about the notion of a film a long time ago, because Deric told me he was writing a book and said it would make a great film. The research was there, so I didn't need to journalistically talk to people."

There are differing opinions on Howell, but Nesbitt remarks he "clearly had a certain level of charm".

"He was a very forceful person whose religion meant a lot to him, but I think we all agree that [for him], God was made in his own image, and he was supremely controlling. This control and self-belief put him in a position where he felt that rules didn't apply to him."

Nesbitt didn't meet Howell, and though he believes that was the right decision, he confesses that he "wouldn't mind sitting down with him for a while".

He recalls chatting with former politician Ivan Cooper, who he portrayed in 2002's Bloody Sunday.

"I said to him, 'Tell me about what happened', and he talked for six hours. I talked to Joe Griffin [who he played in 2009's Five Minutes Of Heaven] and asked, 'What happened when your brother was shot in front of you?' He talked for days. Whether or not that would have happened with Colin, I don't know," admits Nesbitt. "I would have asked him why he confessed... Something I've always thought is, a couple of days after confessing, I wonder if Colin went: 'Oh f***'," he adds with a laugh.

Colin has always denied that financial gain was a factor in the killings and Mark Redhead, the drama's executive producer, has pointed out that "the one thing he's always sensitive about is the suggestion that he did it for money".

What does Nesbitt make of his motives?

"The more we did it, and the more we got to know those characters, at times, you couldn't help but feel you were playing a love story. I think there's a level of psychopathy in there," he adds. "There has to be. But I don't know what motivated the murders. From a religious side, divorce wasn't permitted in the Baptist church, and he [Colin] was certainly aware of banishment. That membership and the position he held there tied along with his need for power, and banishment would have been humiliating for him."

Redhead points out that the attention to detail and primary source material is the reason they felt they were putting a "true story" at the beginning, stating: "This isn't inspired by real events, we're telling a true story".

As director, Murphy adds: "We do know that the drama is factual and that these [murder scenes] are arranged as per the forensic photographs, not just us guessing. The police interviews and courtroom hearings are transcripts verbatim to what was actually said. I haven't allowed anyone to change anything at all."

And Howell's testimony was something to behold. As Henderson observed: "Colin spent the best part of two years preparing for the court case, he had rehearsed his lines. Howell knew he was going to have a captive audience."

For that reason, Nesbitt found the opportunity to re-enact his court testimony "fantastic – because he had planned it so well".

"He had written it so articulately, with the sophisticated argument he put forward," says the actor. "To perform that was wonderful."

The Secret, ITV, Friday, 9pm