Deputy Chief Brenda Lee Johnson (Kyra Sedgwick) is back for another season of solving crime when TNT's critically acclaimed series, "The Closer," returns for its fifth season on Monday, June 8 -- and ET has your sneak peek.

What is the theme for this season?

Kyra Sedgwick: This year's theme is change and, I think, the most obvious change is Brenda being married and there's been some shifts in the squad. And then, in the first few episodes, the cat is unwell and that's a change that she doesn't want to have to deal with -- the possibility of life without her cat, who in some ways is sort of her independent self. I think the cat is the thing that she had before she got married.

I remember when [husband Kevin Bacon]'s dog … when I first met him, he had a dog and Jane was with us for years and years and, I think, that when she finally passed, it was a very big deal because it was the thing he had before I came along, the thing that defined him before marriage and children, and I think that that's a very big deal.

Brenda seems to go from extreme to extreme -- from drama to comedy. Which do you enjoy more?

Kyra Sedgwick: That's a really good question. I am so grateful that I get both within one show. It's a real shocker. I think I like the comedy better, it's fun you know. We have a real ball and it's harder in a lot of ways. You laugh between takes whereas sometimes it can get very, very sad.

There are some sad things that happen in the first couple of episodes this year and I don't like going to those dark places and staying in them too long. I think as I get older, you want less and less to go to those dark places.

Brenda and Fritz (Jon Tenney) continue to have such great chemistry. What might we expect on that front?

Kyra Sedgwick: Well, I think the inevitable next step to marriage is the idea of having children, and I think that that's a struggle for the two of them. I think it's hard for Brenda, who doesn't see the world as a benevolent, loving place.

I think she sees a lot of the darkness of the human soul and a lot of people who behave badly and a lot of things that seem random. It's hard for someone like to that to believe that the world is a loving, safe place to bring a child into, so I think that is a struggle for her and for him.

Can you talk about any guest stars that we might be seeing in this upcoming season?

Kyra Sedgwick: Yes, we have Mary McDonnell coming in for a couple of episodes, who is so great on "Battlestar Galactica." She comes on as Brenda's antagonist. She is an internal affairs officer, which, if you know anything about the LAPD, internal affairs is like the biggest nightmare. And since the Rampart scandal, they're much more prevalent in the community. They're complete opposites, and they're real antagonists and, I think, it's a fun thing for people to be able to watch.

Your character on "The Closer" often has trouble balancing her home and work life. Do you ever struggle with this? I'm sure it's much easier coming home to Kevin Bacon, but is that ever a struggle with you in your personal life?

Kyra Sedgwick: I think that it's always probably a struggle for people that work and also have a family life. I just think it's always a struggle to fit everything in, to balance it, to give something to both, to give as much attention as each thing needs, I definitely think it's probably hard for everybody. But, yes, it's hard, it's not easy, especially when you're 3,000 miles away.