Idris Elba returns to a darker, bigger-scale Luther

Idris Elba returns to his iconic role of Detective Chief Inspector John Luther for the fifth season of the crime drama Luther, who once again confronts the depths of human depravity.

As a series of monstrous killings becomes more audacious, Luther and new recruit Detective Sergeant Catherine Halliday (Wunmi Mosaku) are confounded by a tangle of misdirection that seems to protect an unspeakable horror.

But as the case brings him closer to the nature of true evil, a reluctant Luther faces the ghosts of his past.

Luther Series 5 premieres today on BBC First (StarHub TV Ch 522) and BBC Player.

It was a no-brainer for the 46-year-old English actor, who was named People magazine's Sexiest Man Alive last year, to inhabit the character again due to his "commitment" to Luther.

He said: "I have done it for a few years now, and I always want to come back. I love the show, and I love playing the character. It is a gift of a part. There are so many dimensions to play, and I really enjoy that. Also, we are loyal to our fan base. We want them to get their fix."

How has Luther developed over the five seasons?

The show doesn't change format. We are prescriptive about the type of show it is. We don't deviate from that.

It is a dark, violent procedural.

But in this season, we have upped the scale. This just has more of a cinematic feel.

But Luther is still Luther. He has just got older, as you can tell from my beard.

What have you learnt from playing Luther?

As an actor, I have learnt to find ways to keep the performance fresh and real. I have also learnt to trust the writing, to adapt with the writer and try to make the character deeper.

It is great when you have a really good writing partner like (creator-writer) Neil (Cross).

Also, murder detectives have an incredible capacity to take stress and pressure. They tend to be hard to penetrate because not much shocks them.

As a person, I have learnt what that is, and maybe some of that applies to my life. Not many things shock me now.

Some people have compared Luther to a superhero. What do you feel about that?

Because of the graphic novel styling of the show, I can understand that.

In the same way that a superhero always dons the same uniform, Luther always wears the same coat, red tie and grey shirt.

Also a moody, dark, comic book-looking London is the backdrop. London in Luther is like Gotham City. That is where some of the comparisons with Batman might come in.

Luther is also a mysterious man. He is a murder detective, of course, but he has inner demons, a dark side.

Is Luther popular with real-life detectives?

Absolutely. They love him because he doesn't get into the politics of the job. He gets into finding bad guys in the most visceral way. It is pure escapism.

Would you make a good detective in real life?

I probably wouldn't. I tend to overcompensate. I tend to think people are going to be good. I don't look for the bad in people.

If someone does something bad, I try to look at why. I don't believe in pure evil. As a detective, I think you have to have a suspicious nature, and I don't have that. Part of the job as an actor is asking, "What's the backstory? Why did he say that?" I would take that into being a detective. But Luther doesn't do that. He just gets on with it.

I think I would be a good criminal psychologist though.

How has the show progressed since its debut in 2010?

It started life as a small BBC drama. But over the last five seasons, it has become one of the top shows that people binge-watch. Also, my career has got stronger and more varied over that time.

What does the future hold for Luther?

We would like to see more Luther on TV, but for now, the focus would be on a movie. We want to scale Luther up to a feature film and take it to a much larger audience.