Mary McCormack is back for another season as U.S. Marshall Mary Shannon on the hit USA Network series In Plain Sight, which premieres on Sunday, April 19 at 10 PM ET on the USA Network. McCormack recently held a conference call to discuss the new season, and here's what she had to say.

What about your role continues to challenge you?

Mary McCormack: Well, a number of things. I mean one of the weird things about TV and one of the things that some actors don't like but I kind of dig is that you never know where you're headed, I mean you never know what the writer might think of next. So, unlike a film or a play where you know the entire story and you know where you have to end up, with In Plain Sight and with "Mary Shannon" I never really know what he's cooking up. For example, my relationship with "Rafael" and my intimacy issues and all the push and pull of that; this season is completely different than it was last season. Then, there's more development with me and with the mystery of where is my father and what happened to him. I mean there's just so many kinds of question marks with "Mary Shannon" that that's always a challenge, just sort of trying to figure that out. But I'm trying to think of what else in the role is challenging. I mean trying to make her vulnerable, trying to balance the vulnerability because I don't want it ever to be two dimensional and I don't want her to seem, I mean even though she has sort of bad ass qualities and she's a tomboy and all that, she doesn't really take a lot of garbage, you have to sort of see how she ended up that way and why she ended up that way and where she's weak and where she's frail and where she's girly. So, trying to make her three dimensional and complex, that's always challenging.

There's great chemistry between you and "Rafael" who is played by Cristian de la Fuente. How do the two of you continue to maintain such great chemistry between each other and how will you continue in season two?

Mary McCormack: We really enjoy each other. I'm crazy about him. I'm really just crazy about him. He's a great guy. I mean no one that pretty should be that nice as well and funny and smart. God went to town when he made him. He's just fantastic. I get along well with his wife and my husband gets along well with both of them. Actually, his wife is guest starring in this episode now that we're shooting right now and my husband is directing it. Sometimes I call my husband and I'm in bed with Cristian. So, it's all very odd. It's a really odd relationship. But his lovely wife, Angelica, who's a beautiful actress, is guest starring on this episode and my husband, Michael Morris, who directs many, many Brothers and Sisters and the producer of that show, is directing this episode of In Plain Sight. So, it's all in the family with us.

Why do you think people continue to tune in to see the show? What is it about the program that continues to draw the viewer in?

Mary McCormack: Well, I don't know. I mean I hope it's the same thing that draws me in. Every week I get the script and I'm excited to read it. It's great writing. David Maples is a great writer and he writes interesting stories. Every week, you sort of meet a new witness and I always think there's an interesting story there, but you also have this ongoing storyline of "Mary Shannon's" family and her personal life. I don't know, I think both things are sort of appealing. It's also a nice combination of really dramatic and action-y and sort of some mystery elements and then it's really funny. I mean David is a funny writer. I mean I remember when I read the pilot; part of the thing that attracted me was I laughed out loud three or four times, and I never do that reading a script, even when I know the scene is funny. I rarely sort of chuckle out loud when I'm sitting reading a script alone, and I always do with David's writing. I don't know, hopefully, it's just a fun show to watch. I hope we keep doing it.

I really enjoy the show and I was wondering; we've kind of had a cliff hanger at the end of the last season. I was wondering if the show is going to kind of pick up where that left off and show them kind of getting out of the trouble.

Mary McCormack: No, it does. I love David Maples for this, who writes the show. He didn't at all do that terrible TV thing of just pretending none of that happened and starting over. No, you take off the next day. In fact, he picks up right after I shot this guy. So, you meet me sort of post-stress event and you think, "Well, how's she going to respond?" At first, I'm very, very sort of unaffected by the whole shooting and I'm just sort of like whistling my way through the day, and then as it wears on you start to see it crumble apart and all the post-traumatic stress begins. That's one of the things that I love about the show is that while it's funny and it can be light at times, it definitely still has a really adult sensibility and it's sort of tethered to reality. Even though she's a bad ass and even though she's tough, they didn't make her like a superhero. They didn't make it like there's no repercussion from killing a man. So, I really appreciate that as an actress and I think I appreciate it as a viewer as well.

With her, she has obviously issues with her family relations. Are we going to see sort of a change in dynamic with that ... things are kind of out on the table.

Mary McCormack: Yes, quite a bit. I mean actually in the beginning of the season - honestly, I don't know how much I'm allowed to say or not, so I'll just say everything. In the beginning of the season, my mother - I forget which episode, but very near the beginning of the season she hits sort of a new low in her drinking, which is extraordinary to watch and you think it's going to be funny and it's not at all funny. And then, she decides to try to stop drinking and she goes to rehab. "Mary Shannon's" never known her mother without alcohol involved, so it changes the entire family dynamic, and my sister goes back to school and she decides to try to turn over a new leaf. Because it's television, I don't know how long these things will last or if they'll make it or not, but the dynamic completely changes, and then the mystery of "Mary's" father is still floating and looming and you get some more clues as to what happened to him.

Her partner Marshall is a very interesting dynamic as well. Are we going to see kind of a development in that more?

Mary McCormack: Yes, it develops somewhat. I mean I think it's probably a relationship that's been that way for a long time. So, for it to develop too quickly or change too quickly would be sort of unrealistic because it seems like, at least when we meet them, even in the pilot you feel like they've been together for quite a long time and comfortable in their roles. They've sort of grown around each other. They sort of work as two parts of a whole. But you learn a little bit more about their feelings and my relationship with "Rafael" progresses more and sort of "Mary" decides to try to take some big chances that she's never taken before. It is interesting and fun to watch Fred Weller's reactions to all of that.

What's your favorite scene you've filmed this season, if you can tell us about it?

Mary McCormack: The other night where Fred Weller was playing drunken chess on his computer screen because in the episode I tell "Rafael" what I do for a living and it gets Fred Weller, "Marshall Mann" gets so angry about it and I think not just because someone knows what we do, but maybe even more because I've been intimate and shared this secret with another man. And so it's like involving another man as closely as he's involved maybe and I think that's definitely a big part of it. In the last scene of the episode I come back into the office and he's sitting there playing chess with an 11-year-old Pakistani girl online and he's just loaded. He's really drunk and she's beating him and it's sort of a very sweet scene between my character and Fred Weller's character. I think that might be one of the favorites. And then, there's some good fun shoot-out stuff with season two and I always love doing that. I like all the action stuff.

Can you kind of run us through a typical day on the set?

Mary McCormack: Oh, my goodness gracious. I get there super early. I mean a typical day for me is door-to-door somewhere around 15 hours or 15 to 20 hours usually. Hair and makeup is first and I spend an hour or so in hair and makeup and we all get ready for the work of the day and then we rehearse the first scene. Then, they light the first scene and we shoot it. We start shooting and we never leave the set and we just work all day. That's it. That's our day. We sort of rehearse and act all day long, move the camera and move the lights and do it again and again and again. We've been at it for seven months now. We have about two weeks left and we're a tired group. If you came now, we're almost punch drunk; we're crazy.

The way I view the show is that you essentially have three different families. You have your pretty darn dysfunctional family with "Brandi" and your mother and then you have your work family where "Stan" is the father figure and "Marshall" is a brother figure, in my opinion and then you have "Raf," which he kind of represents the potential for what could be in a highly functional normal family life. Is that how you view it, or do you see it differently?

Mary McCormack: I'm pretty close, and I don't know where this show is headed. So, I actually have no insight in terms of like if "Rafael" would be the-it certainly would be healthy because he's kind and he's gentle and he's nice to her and he knows her well and he sort of forgives all of her rough edges and all that. I mean I don't know where we're headed, but I think you're right. I do view it that way. I think her home family is more like the crazy cousins. I think her work family is probably her primary family. I mean I think "Stan" and "Marshall" are her actual family-family and the mother was never really a mother. I mean I think she raised "Brandi" and sort of took care of "Jinx" from when she was little. But yes, that's nice. I've never actually thought of it as broken up that way. We'll have to see what happens with "Rafael" because it's definitely an interesting-intimacy doesn't come easy for "Mary Shannon." In the second season, she certainly tries harder in that department, a lot harder.

"Mary" is such an independent, career-driven woman and "Raf" is just very traditional. He's a very traditional male. Do you actually think that "Mary" is good for "Raf" in the long run in terms of marriage and family, or do you think--?

Mary McCormack: I think they are a mismatch. My guess is that they're sort of mismatched. I mean he would probably ideally not want her to continue with this work and she's never going to give this work up. So yes, that's sort of a train wreck waiting to happen I imagine, but bless his heart, he's so kind and keeps hoping she'll change and she never changes.

We were looking back over season one and we see that "Mary's" the one taking care of everyone in all three of those families, she seems to be kind of the caretaker. And now, obviously with the season finale, she has - already had baggage, but now she has even more. Is that dynamic going to change? Is someone going to start taking care of "Mary?"

Mary McCormack: Well, I think in some ways "Marshall" does. I mean I think at least she doesn't have to look after him - that's something. I guess that's probably why it's her best friend, because it's the one person she doesn't have to clean up after. I think "Rafael" in season two does- she allows him more of that role. In season two also, and I said this in interviews before because I don't know if it's spoiling anything, but my mother sobers up and goes into rehab and stuff and my sister goes back to school. So, there's a little less of that- I mean a lot less of that sort of caretaking model, which actually is a little bit odd for her. I think we even touch on it in one episode. I think even "Marshall" says to her like, "Your whole identity has been about this. You've sort of defined yourself by their inability to look after themselves and now they're doing it and you don't really know who you are anymore." So, it's interesting because it's that whole thing of when you care-take, when that becomes your role, if people get better and they don't need you anymore, who are you? I think it's a pretty adult theme, but it's a theme I think anyone who has ever done any of that in their life, either side of that coin, knows about.

Sure. That's going to be fun to watch play out because it's going to be kind of a big change for "Mary" as well.

Mary McCormack: Yes, a big change. Yes, she likes to bitch about it, but at the same time her own addiction is sort of looking after people.

Along those lines, is there a particular assignment that you would like to see "Mary" get?

Mary McCormack: Oh, wow. Geez, Louise, I've never thought of that. Who would I like to protect? I don't know. Golly. I don't know. I'm trying to think of like some gorgeous man that I should-- I'm trying to think of a clever answer. I don't know. I have no idea. I'm out of cleverness. My kids are down for an hour nap, so I don't know where my brain is. I'm just happy the house is quiet for a minute.

I'd like to follow-up a little on the comment of your having on the show three distinct families and how "Mary's" dislike of change affects the way things go there specifically in regard to her current uncertainty in regard to "Raf," the changes where her mom and sister have started to smart up but haven't really gotten to a new level, and also in the return episode, the premiere, new people in the workplace and "Marshall" looking after "Mary."

Mary McCormack: Yes, I think "Marshall" even says in one of those episodes early on, "Mary hates change." I think he even says it, yes, and she does. I think anyone new is sort of a bummer to her. It's just because she figures things out and likes the way they work, even if it's bad. Even in the unhealthy family dynamic, at least she was used to it. She had been living in it since she was a little girl and she knew it. Now, her mom is all AA slogans and her sister is sort of in a healthy relationship, which is just confusing. Everyone's just a little bit different and even "Rafael;" halfway through the season he makes a big, big, big change in his own life, a career change and it completely freaks "Mary" out. It's his own life, but she has to redefine her relationship with him. Change does not come easily. I think it's a bumpy season for her and "Eleanor" is a huge change for her because that dynamic-- I mean the dynamic with her work family was so comfortable for her because she was adored. She's adored by "Stan" and he lets her sort of have run of the ship. "Marshall's" her best friend and they've grown around each other like vines and trees. I don't think there's anywhere where she's more comfortable than work. And so "Eleanor" coming in; another woman coming in and a woman so unlike herself, is a huge adjustment. Here we are right at the end of the season and she's still annoying the hell out of her.

It also strikes me that she's introduced at a specific point in time where "Mary" has to kind of reevaluate her relationship with her own self because of all of the crap that's gone down in the last few days of her life. How do you feel that's going to affect your performance in regard to the individuals that you encounter both in the workplace, at home and the various witnesses?

Mary McCormack: I think it's the kind of thing-- for a few episodes it affects it a lot, especially the first one. At first, she's all like "Life is beautiful" and trying to seize the day. You know the way you are when you have a near death experience, I mean everyone talks about sort of smell the roses and live in the moment and all that stuff, and then just how long does that last is the question. It doesn't seem to last that long. She sort of slips back into old patterns. But, I do think she takes a chance with "Rafael." I mean I wonder how much of that is based on her near death experience. I don't know. That's an interesting question. She definitely goes further down the intimacy road with "Rafael" than she's ever been. So, maybe that's due to that.

We have a nice little holiday coming up here - Mother's Day - and I think one of the better portrayed on screen mother/daughters in you and Lesley Ann Warren. I'm a big fan of her over the years. What was it like initially meeting her and then as an actress, working alongside her now for a couple of years?

Mary McCormack: Initially meeting her was fantastic. So like, I was a big, big fan. It was daunting, but thrilling because I just love her work. We both worked with Steven Soderbergh. So, I remember our first conversation was about our mutual love of Steven Soderbergh. And so, I think once we had that out of the way, we knew we were going to work similarly because Steven works in a very specific way and not every actor would dig it. I mean a lot of actors obviously dig it a lot, but it's just very specific and we were sort of having a lovefest gush session about how he works and how he is. And so, I think from that moment on, we sort of knew we were going to work in a similar enough style that we could get along great and we have. We're both really lucky actually. I'm crazy about her husband. She loves my husband. It's all very comfortable. She lives down the street from me in LA. She comes over at Christmastime and spoils my girls. She's great. She's the best.

I love the show. I love your character so much and I just feel it's some of the best stuff on TV. I was just curious; for you, what's been the most rewarding part about doing the show and getting to play somebody like "Mary"?

Mary McCormack: Golly. I mean I love the way David writes. It just feels like a really, really comfortable fit for me and I like that she's kind of grouchy. I mean I love the character so much. There's one episode, and I reference this often because it just struck me when I read it as so unusual for a woman to say something like on TV, she sees a little baby and out of the blue, and pertinent of nothing else, she doesn't sort of continue the thought, she goes, "What's with babies? I don't get them." You never hear women say stuff like that on TV. I just think David has a really fresh approach to, I guess, writing this woman because it's certainly not representative of any other woman. She's a complex part and I like that she's allowed to be sort of grouchy and a little bit angry, angular. I don't know. It's a comfortable fit for me. I'm not proud of that, but it is.

Well, it does seem like that as a viewer, it just fits you really well.

Mary McCormack: Yes, and I get to work with great people and I like the stories and I think it's also an interesting backdrop for a show. We've never seen witness protection and certainly the only thing I knew about witness protection before this was what I knew from Goodfellas, which isn't a lot. I mean it's a crazy world to think that people just up and leave. They do leave like food on the stove and walk out of their house and never call and never talk to their families again and never turn back. So, it's a very dramatic world. It's like high stakes and pretty emotional.

Yes, I didn't know anything about witness protection either and now I'm all of a sudden very obsessed with it.

Mary McCormack: I know. It's crazy. They don't actually even get to tell their families where they're going. We have a technical advisor and one time I was grilling him about this because I just couldn't believe that they didn't get to say good-bye. He said once in a while if they felt the person would be like better, like if it was so emotional, they would stage a good-bye, like arrange a good-bye in a safe place. Can you imagine that scene? We have to do that scene. Can you imagine that scene? I mean what a scene. Often, they don't even get to do that. I said, "Well, how does the family know they're not just dead?" What's to stop the family just from having a funeral or mourning forever and ever or committing suicide or who knows what you'd do with that kind of grief? He said that they contact the family and let them know. They don't say the exact words, but they'll say like, "They're not going to be back, but they're safe" kind of thing. I mean what? It's too much to think about. It's crazy and all for testimony. But, I guess people, when faced with you're going to die or starting over, the will to live rises up I guess.

Maybe along those lines, in playing "Mary," have you learned anything new about yourself over the course of doing this show, portraying her either personally or just in sort of the technical of working on a show like this?

Mary McCormack: I've learned a lot. On that side of it, I've learned an enormous amount. I mean I've worked a lot over the years and I've done even a lot of TV, but I've never been in every scene almost. I have two kids under the age of four, so that and 15 to 20 hour days of work everyday, I certainly have learned a lot. I've learned a lot about stamina and rest and balance and forgiveness in terms of my own guilt about where I'm falling short in my life. Certainly, I've learned more than I ever thought I could learn about that stuff. I guess I learn from the character too. I mean I have some similarities to "Mary Shannon" and so as I investigate things like codependence or what her abandonment issues are and her father leaving, and my father didn't leave, but I mean just in terms of any kind of loss, how that affects how readily available you are for intimacy and stuff. I mean I definitely learn about myself through some of the storylines she's dealing with.

Yes, there are parts of you in her and parts of her in you kind of a thing.

Mary McCormack: Oh, for sure and some of them are just little things, like little, little details that are just coincidences, but are spooky. I mean David Maples wrote it without me. In fact, he didn't even know who I was, but her name is "Mary" and she's from New Jersey, and I'm from New Jersey. There are so many little things. She calls her sister "Squish" and I called my oldest daughter "Squish" when she was little. I know and they're just obviously tiny little coincidences, but the first time I picked up the script, I was like, "This is odd." It feels like it was actually written for me.

How much will post-traumatic stress affect "Mary's" job performance when the show returns?

Mary McCormack: I'm trying to think about-- it's interesting. I wonder how much of her job is affected by it. Certainly it is for a few episodes, which is spread over weeks and weeks. I wonder how much of that continues. I'm trying to think. I guess there's a whole thing that happens in the end. We're shooting the two-part season finale now. The first half is being directed by my husband and the second half is being directed by our show creator, David Maples. So, we're in the thick of it right now. I know there's a big even that happens that will be questioned and brought back to the finale of last year. I mean they'll be linked to that meaning did that affect this kind of thing. It will be back. It will rear its ugly head again, whether I've put this thing behind me or not, this near death thing and the fact that I killed somebody for the first time.

How much would you like to see your character's relationship with your mother and sister evolve? Is there a certain way that you'd like to see it go?

Mary McCormack: I don't know. I mean I think about that a lot actually because this year, my mother is sober. My sister is still drinking, but my mother has gone to rehab and it's sort of 12-steppy. That's interesting because there are all kinds of different tensions, but I liked it the other way too because there was a lot to play with that. I can't imagine that she doesn't slip at some point. I think just in terms of being realistic and knowing "Jinx" at all, I can't imagine that she doesn't return to the dark side soon. But, we'll see. I could be wrong. David Maples surprises me all the time.

How do you see the show as compared to other police dramas?

Mary McCormack: I don't know. I mean I think our show is pretty special for a number of reasons. One, I just think witness protection is pretty interesting and you don't see it in many other police dramas. I mean it's definitely a singular backdrop. But also tonally, I think our show is unusual. I mean it's not strictly a drama. It's also really funny and finding the balance is sometimes tricky for us. We have to really think about like when the scene changes. Sometimes it changes within the scene and sometimes it changes scene-to-scene, but I don't know. It's an odd tone, our show. And so, I think it's different for that. Also, a lot of cop shows are just procedurals. I mean we're not CSI. We're not what's the Katherine Morrison show. There are procedural shows where every week you have a mystery and then by the end of the hour; all the Dick Wolf shows, in the end of the hour, the mystery is solved and next week you have another mystery. Ours has that, but we also have the ongoing story of my life and my relationships and my work relationships, my boyfriend relationship, my family relationship. So, I think our show is pretty special for doing all that within the hour and hopefully doing it well. I mean that challenge is making sure we do all of it well.

Mary McCormack comes back as Mary Shannon when In Plain Sight returns on Sunday, April 19 a 10 PM ET on the USA Network.