Like many parents, James Nesbitt has experienced that heart-stopping “crash-zoom-lens-Spielberg-close-up”, where for a few seconds, you think you’ve lost your child.
“It’s happened in a supermarket with me,” explains the 49-year-old father-of-two, who grew up in Northern Ireland.
“A lot of the time, they weren’t lost, they were just running away from me [and were] in aisle 14 by the Haribo. But it’s a moment of horror.”
Thankfully Nesbitt, who has two daughters - Peggy and Mary - with wife Sonia Forbes-Adam (the couple split last year after 19 years of marriage), hasn’t experienced the trauma of having a child go missing in real life, but it’s something he’s been thinking about a lot recently, as it’s the subject of his new series, The Missing.
In the BBC One thriller, he and Frances O’Connor play Tony and Emily Hughes, the panicked parents of five-year-old son Oliver, who vanishes in 2006 while they’re on a family holiday in France.
The action takes place over eight episodes and eight years, jumping between flashbacks and present day, detailing the devastation Oliver’s disappearance causes his parents, who are often at odds with the French police and struggle with the language barrier and foreign procedures.
Filled with guilt that Oliver lost grip of his hand while they were watching the World Cup in a crowded bar, Tony finds it impossible to move on with his life.
It was a story that gripped Nesbitt, who actually began studying for a degree in French before dropping out of university, and eventually enrolling at London’s Central School of Speech and Drama to pursue an acting career, despite the heavy subject matter.
“Well, it’s not light,” he says. “We’re hoping that the thriller element of who’s involved and what has happened to Ollie will counter [the bleakness]. A monotone bleakness would be unbearable in a sense, and so I think they’ve balanced it that way.”
Flipping between filming scenes in 2006 and 2014 meant that Nesbitt spent an hour and a half in the make-up chair having a rather “itchy” fake beard stuck to his face this morning.
“This here is actually the best fake stubble in the world,” he says, motioning towards his salt and pepper chin.
By 2014, Tony is an “isolated, pitiful creature” who is clinging to the hope that his son is still alive and can be found. It’s a position Nesbitt would find heartbreaking to be in.
To many, Nesbitt remains best known as the lovable Adam from hit comedy drama Cold Feet. He’d had a string of TV jobs before that, but it was the popular series, which ran from 1997-2003 which made him a household name.
Mixing light-hearted parts with grittier roles seems like something the actor, who also stars as cheerful dwarf Bofur in The Hobbit film series, is quite comfortable with.
“It’s funny, every day I say to Fran [O’ Connor] at some point, ‘I’m going back to comedy’,” he says of filming The Missing.
“I’ve done many jobs, different degrees of emotion, and you’ll look through the script and go, ‘God, I’ve got that love scene that day’, or, ‘I’ve got that massive day with that big heavy sequence in a couple of weeks’, but with this, it has honestly been every day,” explains Nesbitt.
“One day I had been a wee bit snappy with Tom [Shankland, the director] and felt apologetic about it, and he said, ‘You’re ripping your heart out every day’.”
He’s aware how this might sound though, and doesn’t want to seem “wanky” when discussing his career, so leaves things on a pragmatic note.
“Listen, I’m an actor learning lines and saying them in the right order,” he says. “But to get this gig - these are scripts that people were quite keen to do, it’s a good part.
The Missing , BBC1, Tuesday, 9pm