Josh Hartnett's back on the small screen in new Sky Atlantic drama The Fear Index. Along with co-star Arsher Ali he talks to John Byrne about the high-tech thriller adapted from the Robert Harris novel.

Let me tell ya: Josh Hartnett’s deffo one of the good guys. He’s had a long and pretty impressive career in acting, mostly in movies but also on television. Primarily regarded as as sex symbol, he deftly bypassed that side of showbiz and got on with building himself an impressive and long-lasting career.

This time around, the now 43-year-old stars in new Sky Atlantic drama The Fear Index - based on the Robert Harris novel of the same name - as Dr Alex Hoffman, a technology genius who experiences a waking nightmare of the worst 24 hours of his life.

The cast is impressive. Alongside Hartnett there’s Arsher Ali (The Ritual, Informer) as Hugo, Hoffman’s hedge fund business partner and best friend; Leila Farzad (I Hate Suzie, Innocent) as Gabby Hoffman, Alex’s wife; and Grégory Montel (Call My Agent) as Detective Leclerc.

Dr Hoffman is launching an AI-driven system that exploits fear in the financial markets and operates at lightning speed to make big returns. The promise is billions, and the rich like nothing better than to get richer..

But the big day Alex and Hugo had planned turns out rather differently. What follows is the worst 24 hours of Alex’s life - cutting across reality, memory and paranoid fantasy,  forcing him to question everything he sees with his own eyes. 

In the pulse of Geneva’s financial district, Alex’s sanity is shaken after he is viciously attacked at his home by a man who knows all of his security codes.

After more unexplained occurrences, Alex becomes convinced he’s being framed. But as secrets surface from his past, will anyone believe that he isn’t just losing his mind?

Hartnett is no stranger to Ireland, of course, having moved here during the filming of the first three seasons of gothic drama Penny Dreadful. So it makes sense to start our conversation there . . .

Josh Hartnett

John Byrne: Josh, did you enjoy your time living in Ireland, and what do you most recall about that period?

Josh Hartnett (JH) I loved it. We had such a good time in both Dublin and Dalkey. I was there for three winters. I don’t really want to talk about the weather, but it’s the coldest I’ve ever been. And I’m from Minnesota.

It’s that horizontal rain that comes in off the sea that’s just like . . . you can’t escape it. You get drenched and cold. But I’d a really good time.

Right across from where I was staying was Finnegan’s, the famous pub. Obama called there - isn’t that right when he visited Ireland?

Pretty sure you're righ there. So, as for the show, are you guys fans of Robert Harris, the author who wrote The Fear Index that the show is based on?

JH: Very much so.

Arsher Ali (AA): What was the thing he did with Ewan McGregor? That was the only one I saw . . .

JH: The Ghost!

AA: Yes, that was it. But otherwise no. This is all new to me, which is a great answer!

Arsher Ali

JH: I became a fan after reading this book, because this originally came to me from way back when. When I read the book I was really intrigued by his writing style, and started reading up on Robert Harris.

I found out he was mostly writing about historical fiction, and this fits right in here, in an odd way. It’s more about time and place, and the way people are interacting in that time and place, interacting with technology, and I loved it.

I really loved the characters, and what it was saying. A Frankenstein analogy for our time, which is exactly what we need. So I became a big fan of his.

TV is up there with movies now. It seems the lines that used to be very distinctive between them are now fading . . .

AA: The lines are blurred now. You obviously get more of your auteurs in film, but I think from an actor’s perspective, you’re just getting more time with a character. You get more time to explore the extremity, instead of being on the rails for 100 pages, or whatever.

And also, if you look at the kind of people you’re attracting to TV now, its lines are very much blurred.

Leila Farzad

JH: Nobody looks at the industry these days whether it’s going to be a shorter format , like a film, or a longer format, like this - it’s just 'Is it a good story? Is it told well? Are there going to be good people involved?’

And I think that’s more akin to the day it was, or always has been, in Britain - and less so in the United States. And I think that’s moved over there [the US] now as well.

Since you started, how has the industry changed - how has fame changed?

JH: Fame is always unnatural, I think. I think it’s difficult for anyone to get a handle on what that means to themselves. And I think it’s always changing.

For me, I’ve always been a terrible celebrity. I don’t really do all of the things that celebrities mostly do, so I’ve kind of stayed outside of it. Which is lucky. For me. And I continue to make what I think is interesting work.

Josh Hartnett

The nature of the work itself has changed, for sure. Hollywood is less on a pedestal than it used to be. It’s more democratic, in a way. And every job, because most people haven’t worked together before . . . every job feels different.

I think it’s becoming much less elitist, and much less revered within the general public. Everybody feels that they know what everybody’s business is, and that’s because people are flogging themselves on the internet.

There’s more of a dialogue, let’s put it that way.

Are you guys fans of social media or do you find it annoying?

JH: I don’t have any social media. We’re Luddites!

AA: I didn’t understand what Tik-Tok was. I didn’t know how it was different from other stuff.

JH: I like to promote a film the old-fashioned way, when we talk to you guys.

Leila Farzad and Josh Hartnett

How do you feel about this world that your characters are in?

AA: Well, for me it's a world I didn’t really know about. It’s not something I’ve explored. That’s part of the attraction, in terms of it being this world that’s most secretive.

Especially when it comes to the actual tech, and the actual stuff, that people are putting all their literal stock in, you don’t know about it. These mad geniuses like Josh’s character. You don’t know of them.

All these kind of mad scientists that basically control a lot of the world’s finances, and that’s quite scary.

JH: What it suggests to me is that how long those tendrils of the financial institutions are, and their power within the structure as it exists. And if something like this were to happen, it would be unchecked.

And that’s the most terrifying thing about this book and this show to me. The concept of unchecked power. And marry that with the concept of a character with an extender complex, which is another one of my biggest fears.

I think losing your mind is the most terrifying thing that can happen to you. But what would be even worse would be you are seeing things clearly - but no one believes you. And so you’re almost driven to madness through that.

I find those themes really interesting and I loved the book, and really enjoyed being part of the show.

The Fear Index is on Sky Atlantic on Thursdays at 9pm