The actor takes us inside the mind of a serial killer.
ENTERTAINMENT WEEKLY: In this episode, the team is in Martin’s territory.
Is this the most screen time you’ve had in this series so far?

Phil Caruso/FOX
I can sometimes find it quite difficult to remember what’s in each episode.
But this particular episode was a very, very different field for me.
My experience of working on this show has been a kind of opening up as it’s gone on.
So things have opened up more and more as it’s gone along.
Right, it’s safe to say Martin is having a lovely time throughout most of this episode.
I’m working with my own son on a case in my prison.
Martin’s just in heaven.
I got to play basketball, for instance.
Yeah, you got some outdoor time!
It’s funny because Martin would love having outdoor time.
Michael doesn’t love it that much because it’s quite cold.
I quite enjoy being in my cell with my cardigan on.
One of the people Martin gets some quality time with in this episode is his daughter, Ainsley.
How much do you think he’s enjoying this newly discovered murderous streak in her?
Or is he more interested in just spending time with her regardless of the reason?
I think it’s a lot of things for him.
There’s a real delight in seeing this flower that has grown in the dark.
She’s this extraordinary flower that is actually grown in the dark, without him feeding it at all.
There’s a special delight to that.
That creates a special connection for Martin.
That’s kind of terrifying.
Yes, it is terrifying.
How much do you think Martin resents Malcolm deep down for sending him to prison?
Is that something we’re going to get to explore more?
Yeah, I think so.
The version of Martin that he allows people to see is such a tiny portion of him.
It has an oversized place in the world because it’s how he interacts with the world.
That is a construct he has created.
What is actually going on for him is very different.
We just don’t see that very much because it works for him for people not to see it.
We get a sense of what’s really under there.
I think there are currents within him that even he only vaguely understands.
There is huge oceans of rage in Martin.
Yes, because it’s in his interest for people to not think that he’s a monster.
That’s how it works."
You use what will work for you.
There were people who had crushes on Ted Bundy.
Use what you’ve got.
Martin uses that and it works very well for him, and it still does in prison.
Do you know a lot more about Martin’s past than we’ve learned on the show so far?
Have the writers filled in some of those years of serial killing for you?
A lot of the time it’s quite useful for people to not know his past.
We’ll still be finding out about people he’s killed come season 10.
So Martin and Jessica also had a cute but not really cute at all co-parenting moment in this episode.
Is there anything you’re free to tease about what’s to come between them this season?
In a way, that’s the motor of the show, isn’t it?
Jessica is never going to be free of Martin.
There’s a very special enjoyment in that for him, which is very dark.
There’s also a real rivalry between them, a parental rivalry.
Eek, poor Jessica.
Speaking of women in his life,Catherine Zeta-Jones is joiningthe show soon.
Can you tell us anything about her character and how she’ll affect Martin?
Prodigal Sonairs Tuesdays at 9 p.m. ET/PT on Fox.
This interview has been edited for length and clarity.