Warning: This post contains spoilers fromPeaky Blindersseason 6.

When Thomas Shelby (Cillian Murphy) walks into a room, people pay attention.

Or perhaps it’s the razor blade sewn into his cap.

Cillian Murphy

Everett Collection

Tommy is as much an intellect as he is a gangster.

Much like the cap on his head, he hides his lethality just under the brim.

It was a role Murphy knew he wanted, and one he was willing to fight for.

Peaky Blinders

Cillian Murphy on ‘Peaky Blinders’.MATT SQUIRE/Netflix

“In fact, I’d probably played the opposite up to that point.

And it wasn’t.

Now, a decade later, Murphy has helped make Thomas Shelby one of television’s most interesting characters.

Peaky Blinders

Cillian Murphy on ‘Peaky Blinders’.MATT SQUIRE/Netflix

What has your experience been with the popularity ofPeaky Blinders?

We were a little show on BBC Two and the BBC does not spend much money on advertising.

Between series 2 and 3 for me was really when it started to become this phenomenon.

What do you remember about that first meeting?

There was slight hesitation because I’d never really played that physically imposing sort of hyper-masculine throw in character.

In fact, I’d probably played the opposite up to that point.

It’s just a good story, but there is a kernel of truth in there as well.

But that’s the thing about acting, you shouldn’t be limited.

What is it like to sit with a character for so long?

That’s amazing, I’ve never had that experience before.

Did you have any traditions or things you did to get back into character every season?

It never became easier, like I couldn’t do it now.

It wasn’t just putting on a cap.

It’s always a process getting back in.

It’s a lot of work.

Steve had very consciously written the cap because that’s where their name comes from.

That was very much a part of it.

It wasn’t all totally in line with how exactly the clothes were worn.

We would tailor them to suit each actor but they’re hugely flattering.

It’s very flattering to wear a three-piece suit for a man and that cap.

When you put it on you kind of feel like the character.

And then all of a sudden everybody started wearing them, that was the crazy thing.

Everybody started wearing the suits and the caps.

One of my favorite things aboutPeakyis how it’s never summer.

They’re always wearing peacoats.

[Laughs] It’s true.

All of us were just baking.

We just skip that season inPeaky Blindersland.

It was difficult shooting because it’s pure wool and layers of it.

We like it nice and gloomy.

[Laughs]

How much of Tommy’s arc did you know going into each season?

Would you know where it was ending?

We always know where we’re headed.

You never know what’s going to happen.

That’s what’s so brilliant about his writing, it’s never predictable.

How do you think the series has benefited from having Steve write every episode?

It’s been one of the most important aspects of the show.

He’s written 36 hours of television, it’s phenomenal.

What drives Thomas Shelby?

That is an amazing engine to have as a protagonist because everything is like, “Why not?

So it was that combined with this ambition.

He’s burdened with this intellect.

It’s a combination of things but the one thing that holds is this relentlessness.

What was it like to play this version of Tommy?

It was very interesting.

That was something I couldn’t have predicted.

He was sort of defined by his whiskey, how much whiskey he drank.

But the drink was maybe becoming an impediment.

It’s very much in the story, that absence.

Have there been moments when you weren’t happy with Tommy?

Sometimes I find the violence and the disconnection to the violence difficult.

If someone gets injured, they stay injured.

But I struggle with that part of it.

But he is a contradictory, complex, difficult character to play.

You’ve got to put aside your own moral compass and go with it.

So much of this show is close-up shots of your face.

What’s it like to film those?

I think it became part of the language of the show from the beginning.

In the very first series there was a lot of close-up work that we wanted to do.

Close-up acting is some of the best because it’s when you see a character think.

The series has wrapped.

Did you do anything to shed this character or say goodbye?

I mean, I grew my hair out, but I do that every year.

I don’t really have any perspective on it.

But I do hope we’ll make a film andSteve is very keen to make a film.

There is more life in the old dog yet, I think.

This interview has been edited and condensed for length and clarity.

Peaky Blindersseason 6 is out now.