It's been 25 years since Tim Robbins stole the show as Andy Dufresne in The Shawshank Redemption - and now he's set to tread a new Stephen King multiverse in psychological-horror series, Castle Rock.

Joining the second season - which intertwines characters and themes from the fictional town of Castle Rock, including budding psychopath Annie Wilkes (played by Lizzie Caplan) - the 61-year-old actor will play Reginald 'Pop' Merrill.

Pop is the patriarch of the Merrill crime family who, living out his dying days, is on the path to redemption from his dark past. So what else can he tell us?

How would you describe the character of Pop?

He's kind of the crime boss of the town - a loan shark, morally complicated - who is hiding things from his past. He's in his last days; he's dying. And he is trying to make amends for some of the mistakes he's made. I can relate to his struggle. I mean, who doesn't want to take some things back, like actions they've taken in the past? But his sins are a lot more extreme than mine.

You said you've always wanted to play a mob boss, too.

Yeah, I grew up with mob bosses around me when I was a kid, and so I kind of know of this guy. At least I don't really know him, but you know, I am aware of how they act and what it's all about. I had a fun time; it's fun to be the bad guy but he's not quite the bad guy. He's complicated, which is another good thing.

You haven't done much horror, other than jacob's ladder. what drew you to this?

As with everything I do, it's all about the script and whether the character is something I haven't done before. When I first became famous, I got a lot of offers to do roles based on the role I had become famous for, which was Bull Durham. So I got a lot of ignorant hunks and I was not interested in that at all. I think the first thing I did after that was Eric the Viking with the Monty Python crew; that seemed like a logical follow-up! I get bored easily. I like stuff that's challenging and which offers new ground for me to till.

What do you think gives castle rock international appeal?

Everybody likes a good scare and thematically it talks about the sins of our past; that's something that's universal. And there's something about Castle Rock as a place. You know when you're looking for an apartment, you walk in and get a kind of chill and you say, 'I can't live here'? Whatever that unspoken thing is - the vibe or the feeling you have - just imagine that in an entire town. It's a town that hasn't dealt with its own sins and because it hasn't dealt with them then the ghosts and the demons will reappear.

What scares you in real life?

If I ever admit what my phobias are, then it's like Room 101. You don't want people to know that stuff. But it's pretty terrifying what's happening with the environment. That's a large-scale horror movie with consequences that will affect us all. Meanwhile, my president is saying that it's all a hoax. Apparently, he's smarter than every scientist in the world!

How did you find returning to King 25 years on?

I get asked that a lot, but I didn't think of it that way because they're so wildly different. That's a testament to Stephen King's talent, that he's able to write effectively in so many different genres. He can write a story that terrifies you and keeps you up at night, then he can write a story that reminds you of your humanity - such as, in the case of Shawshank, the story of a friendship between two men over a long period of time.

What is it about King's writing that traverses generations?

He knows human behaviour in its extremes and in its subtleties at the same time, and he's open to and aware of that human behaviour. Most writers have to struggle to make a book every couple of years, three years, and Stephen just keeps churning them out.

Is Shawshank the film you still get asked most about by fans?

It depends where I am. Sometimes it's that film, sometimes it's Jacob's Ladder, sometimes it's Bull Durham, sometimes it's The Player or Mystic River. People have different affinities, but Shawshank is the one that feels like it affects people the most profoundly. I've had people say that it shifted their perspective on life and that's a pretty intense thing to hear - but also an honour. I don't think a film like that would get made now, though. They don't make big-budget dramas, at least not for the big screen.

Finally, talk us through your career highlights - there's been a fair few!

The Secret Life of Words is a beautiful film that won a whole bunch of awards in Spain, but which I felt didn't get a proper release in my country. Code 46 is another beautiful film. I'm proud of Catch a Fire, which I did in South Africa. Cradle Will Rock is another favourite. I once asked Robert Altman 'What's your favourite film of yours?' and he said, 'I look at my films the way I look at my children - I love the ones that get the least attention'.

The second season of Castle Rock is available on STARZPLAY from Thursday, February 13.