James Nesbitt has said his new series The Missing has reminded him of why he wanted to be an actor.

The Cold Feet actor and Frances O'Connor play the panicked parents of five-year-old Oliver, who vanishes in 2006 while they're on a family holiday in France, and James revealed he was hooked by the story despite the heavy subject matter.

"Well, it's not light," said the father-of-two. "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."

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.

James said of making the BBC One thriller: "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.

"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'."

James, 49, went on: "Listen, I'm an actor learning lines and saying them in the right order. But to get this gig - these are scripts that people were quite keen to do, it's a good part.

"I wouldn't say it's a gift, because it is hard, but if you're serious about acting and your job, and have done a lot and had an amount of success, it's easy to rest on the laurels of that lucky success.

"And when something like this comes along, it reminds you very much why you wanted to be an actor."

:: The Missing starts on BBC One on Tuesday, October 28.