If it's another network medical drama, that must mean we get a new hot-but-messed-up doctor, right? Bingo! NBC's "The Night Shift" (premieres Tues. May 27 at 10:00 p.m.) gives us Dr. T.C. Callahan, who brings a dose of amped-up crazy to the role of E.R. savior. He's good looking, he's reckless, and, oh, he may have PTSD following a stint in Afghanistan. It may not be a particularly sexy twist (you won't know whether to root for him getting back together with his co-worker ex Jordan or pray she runs for the hills), but it was an angle that appealed to star Eoin Macken ("Merlin"). 

I talked to the actor on the set of "The Night Shift" in Albuquerque (which was decidedly less glamorous than, say, that of "Grey's Anatomy") and found that the grittiness of the show (there is a butt box) as well as the unpredictability of T.C. clicked with the Irish actor, and not just because he didn't need to shave that often. Macken, who's also a writer and director in his own right, explained why T.C. isn't as violent as he seems, why this show isn't a mini-'Grey's Anatomy," and why accents are fun for everyone. Go ahead, try it!

You're a writer and director. Do you think that gives you a different skill set? 
I don't know. I think it would be very disingenuous of me to say. I think what's really fascinating is that TV is a writer's medium. I don't have to stay in control as I would if I were directing a film. And the PTSD thing is really interesting, because from what I've explored, you have to be very careful about [it]. I've talked to a couple of guys who are ex-military who've suffered from it a little bit, and I don't think it's fully understood what PTSD is, not just in soldiers but in life in general

I'm curious to know how this is going to manifest in T.C.
I am as well, because I think it's one of those things that can manifest in many, many ways. What's important is to not make it too explicit, like he has PTSD and make it a big event. I think it's very small things that happen now and again, then it comes out the way it would in life, events trigger something the way it would in life. Certain aspects of the character are heightened because of PTSD, and that's what's interesting about it. 

So he's not going to start crying in the middle of surgery.
No, no. These kinds of things that people try to control, like TC, he tries to control whatever happens to him, so it's not a conscious "I have some issues I need to deal with," but something happens every now and again.

He's very secretive. 
He's not very open with his emotions. I think he actually emotes quite a lot, but it doesn't come from his own personal things. 

But he also seems really angry.
Not entirely, actually. 

There's a lot of punching in the pilot, though. 
But he's really a very caring person. I think when he starts to care, it becomes heightened from an emotional point of view, because everything's on the edge. That's what's interesting about TC as a character, the parameters are different than for a lot of people, because if he's gonna go somewhere, he's gonna go hard. If he's gonna go glad he's gonna go all the way over there, if he's gonna go sad, he's gonna go all the way over there. That's what makes playing TC fun. You're not quite sure where he's gonna take these things. 

Usually when you have two exes working together, it's just about guessing when they're going to hook up. Having one character with PTSD breaks the chain, in some respects. This isn't going to be "Grey's Anatomy."
I think it's interesting, and you're right, because there's always that trap of, okay, exes working together, they're obviously going to get together and [expletive] or some crap like that. The thing about it is, it's a very destructive relationship, but not for TC but for Jordan's [Alexander, played by Jill Flint] character. For TC it's actually a very calming thing. For Jordan, it's not. It ends up being very difficult for her, and he is aware of that, but isn't very intelligent about it. He knows it's not good for her, but because it's good for him, he plays up to it and feeds it. He's slightly selfish about it. I think that's what's interesting about their relationship. It's not going to be oh, let's dump our exes and go off with each other. They're not good for each other, and I think that's what's fascinating about watching people who stay together and you know aren't good for each other. 

So we won't be rooting for you two. 
It's a very tentative thing. It's not like, great, they're going to get together and live happily ever after. It's also not going to be the stereotype of they get together and it's a disaster. What's interesting about it is Jordan's character is very, very strong, so she's not gonna let TC be destructive, but where does that stop? I don't even know where that's going to go yet. 

Is it fun for you, playing an adrenaline junkie? You have to babble all this medical jargon in the pilot, sometimes while hanging upside down.
The medical stuff is cool. I have no idea what I'm saying, so the medical stuff is fine. As long as you say it really definitively, everyone thinks it's perfectly fine. You have to totally believe in what you're saying even if you have no idea what it means. But really, I do have a vague idea of what I'm saying. I'm being flippant. But it's challenging to say stuff while doing something physical. I think for me, when it gets harder, it gets more interesting. Like anything. The more alive you become, it's a tiring character to play because it's heightened, but you get to do shit. 

For an Irish guy, how is Albuquerque?
I'm genuinely having a great time, because I like open space. I've been doing a lot of photography, doing portraits of people and landscapes. For the moment, I live in Albuerquerque, but I'm from Dublin. I lived in London for two years. I'm in a good mood if every day I'm in the sun. 

So, writer-director-actor guy, what else do you have on your to-do list? 
I spend a lot of my free time writing. It's really nice. I find when I'm doing stuff, I do more stuff. When I travel, I do stuff. But I'd work for twenty hours a day doing what I love to do. Okay, maybe 18. I do like sleep. 

How are you enjoying the accent?
I called a buddy of mine when I was on set the other day, and he thought I was talking strange, but doing an accent is fun because it informs the character. It makes you feel more like you're in character. You should do it. Try it! Do it for interviews! 

Liane Bonin Starr is an author, screenwriter and former writer for EW.com. Her byline has appeared in the Los Angeles Times, Variety and a lot of other places. Her last book was called "a scandalously catty, guilty pleasure" by Jane magazine. Expect the same from Starr Raving.