Let’s start before Broadchurch. What was your all-time favorite mystery show?
Anna Gunn We always said Cagney & Lacey was our inspiration. That was something that made us laugh nonstop, not because this is like Cagney & Lacey, though we could be a team like that —
David Tennant And I’m playing Tyne Daly.
Gunn Yeah, I’m the blonde and you’re the brunette. So that’s my ridiculous answer.
Tennant I’d go with Murder One. That was such a novelty because it was one story told over a number of episodes, like Gracepoint.
Gunn That was great.
Anna, had you seen the original before you started on Gracepoint?
Gunn I saw the original and was just head over heels for it. It was brilliant. I know that some of the actors did not watch it because they didn’t necessarily want to be influenced, and were a little worried about having somebody else’s brilliant performance hanging in their heads. But in this case [Broadchurch costar] Olivia Colman and I are so different from each other, and I thought it would serve me to watch it.
Coming off Breaking Bad, I’m sure you had plenty of options. Why this role?
Gunn It was everything I wanted after playing a character like Skyler, who is fairly buttoned-up and wound rather tightly. I was delighted to see this whole human being with a lot of different colors to her. She’s tough and she knows she’s good at her job, but she’s also got vulnerability and some insecurity about whether she’s doing things correctly.
David, was there a sense of déjà vu doing this a second time?
Tennant I don’t think it was as much as everyone expected. Actors are used to repeating things. On stage you do it eight times a week. Telling the same story is not foreign to us, and this didn’t even feel like that because you’re telling it with different people and telling — at times — a different story. [The roles] felt very different in my bones.
This is such a serious drama. How do you combat that on set?
Tennant It was a continual Cagney & Lacey meme. It probably drove everybody else mad, but we found it hilarious.
Gunn I know, and I still do.
Tennant I’ve probably got about 20 photographs on my phone of us pointing guns in a Cagney and Lacey manner.
Since the endings are different, how does the quality of the Gracepoint ending compare with Broadchurch’s?
Tennant It would be odious to compare. What they have is a very different note, which is thrilling for me. I feel like I’m almost saying too much just saying that.
Anna, there’s talk you could return as Skyler in the spin-off Better Call Saul. Which part of her story would you most want to visit?
Gunn Well, it’s a prequel, so it’s before Saul meets Skyler. Anything could happen, since Vince Gilligan is a genius. But I don’t believe she’s met him before. Maybe she got into a fender bender, so she could only afford that kind of lawyer.
Speaking of old roles, Peter Capaldi told us he sometimes texts you, David, for advice on Doctor Who. What advice have you offered him?
Tennant He needs no advice from a whippersnapper like me. All we’ve done is compare experiences. It’s an unusual show to be part of — it comes with a lot of attention, most of which is lovely, some of which is overwhelming. I’ve been a witness group for him. He’s a brilliant actor, and I’m very excited to see him in that part.
If a third country asks you to star in its version of Broadchurch, would you do it?
Tennant [Laughs] The trouble is, my French isn’t that good.
Tennant But I’m taking Icelandic lessons, so fingers crossed!