Arriving in the UK on Channel 5 next week, the show features Jim Caviezel and Lost star Michael Emerson as a former CIA agent and a mysterious billionaire, who end up teaming up to prevent crimes that haven't even happened yet.
Taraji P Henson stars as an NYPD's Detective Carter, who quickly forms a bond with the two men and helps them protect New York City. Digital Spy caught up with Taraji to talk about the show.
What can you tell us about Carter and how she fits into the show?
"Carter represents the moral compass of the show. There are these two vigilantes who are off doing good things for people, but Carter doesn't quite know that yet at the start of the show. But then when she finally meets the man in the suit and finds out that he is preventing bad things happening to good people she is on board. And she starts protecting them. She needs to watch them.
"Carter is a straight cop and she's by the book. She has a battle because what they are doing is against the law, but it's also what she believes in."
What's her relationship like with Finch and Reese?
"When you start watching the episodes, you'll see here develop an incredible friendship with Reese. They both have military background so part of her understands him. But then she wants more information. She always wants to know how they understand and how they know what's going to happen."
Will we learn more about her character and background across the first season?
"Oh yeah, they love to peel back the layers slowly on this show. Characters are brought in, then they leave, and then they're brought back and each time they bring new questions. I feel like there are layers of all the characters to be revealed, but Carter especially. This is the first season and you know that I have a son, but it's all done very slowly and cleverly. The writers keep the audience wanting more."
Watch the Channel 5 trailer for Person of Interest:
The show was one of the biggest hits of the season in the US. Did you know it was going to be a huge success when you signed up?
"I'm always confident when I sign up for a project that it's going to be good. That's why I sign up for it. But I admit that I thought this show was a bit too dark for CBS. I didn't think they'd pick it up and then run with it the way that they have. I was totally shocked with the support it's got and the reception that it's had."
You are more famous for your movie roles than work on TV. What are the differences between the two?
"I am more a feature film actress so I'm used to taking my time with scenes. Filming one page a day. With TV, the pace is so fast, the scripts are coming at you, the directors are firing things at you, it's breathtaking. And the most amazing thing is that the writing on this show is so good. Each episode is almost like a mini-film. I thought this was the closest I'll get to making a feature film for TV."
Jonathan Nolan has had huge success with this show and the new Batman franchise. What is it about his work that has such mass appeal?
"They tend to stay away from what the audience wants. That's the secret. And that keeps an audience engaged. Nobody knows what's going to happen. We don't know what's happening and we've got the scripts! Just when you think they are going to go one way, they switch things up."
Are you scared about the prospect of playing Carter for a possible five or six years?
"That's what makes a TV show exciting, scary and brilliant at the same time. It's scary as an artist. In feature films, you know the beginning, the middle and the end, so you know your character. You know everything about them. In this, you don't, which makes it tough. All the backstories are still being created and developed, so you have to trust the writers. And I trust these writers so much, because they're so good, they never stop amazing me."
The show touches on subjects such as post-9/11 paranoia and mass surveillance. Was that a subject which interested you?
"The show has actually made me paranoid now. I wasn't before, but I definitely am now. I am totally paranoid now. Haha."
Does Carter get involved in any of the action on the show?
"In the first season? Oh yeah! Oh yeah! There's only so much that Reese can do on his own. He needs me more and more as the show goes on. He can't take on 20 ninjas. Well, he could, but he'll need my help. I'm his extra muscle."
Did you embrace the action scenes?
"I love it. Carter is so sexy. A girl with a gun, who can kick ass. Of course that's sexy, of course I love it. What girl wouldn't want to do this part?"
More people are moving from movies to TV. Why is that?
"I can't speak for everyone, but personally I told my team that I didn't want to do television. I was turning down TV, season after season. But when this came along and you have names like JJ Abrams attached, Jonathan Nolan attached, I know their history. We all know their history. I just thought this was good company to be in. JJ and Jonah are two men who have now successfully worked on movies and TV, proving that it can be done. And of course, there was the writing. The writing was so incredible, I couldn't say no."
You've just worked with Idris Elba on the film No Good Deed. What was he like to work alongside?
"He's quite ugly and he's quite difficult on set.... no, of course not. Idris is incredible. He's amazing and I love him. I'm so glad we worked together. I had that script since 2008, so to finally get it in the can and finished was incredible. And I can't imagine anyone ever being able to do that role other than Idris. I'm glad we waited."
Person of Interest starts on Channel 5 on Tuesday, August 14 at 10pm.