If you watch "Chicago Fire," then you may already be acquainted with some of the characters on its sister show, "Chicago PD." It may be busy and demanding, balancing a main gig with another job, but for an actor, it's a dream come true.

Sophia Bush, best known for her role as sassy Brooke Davis on "One Tree Hill," is playing a bad-ass of a different sort. Det. Erin Lindsay is one of the members of the CPD's intelligence agency -- working under Sgt. Hank Voight (Jason Beghe), with whom she has a mysterious relationship -- and is as tough as they come.

HuffPost TV Canada spoke with Bush, who may be the coolest chick on the planet. She chatted about her new-found love of Chicago (despite its frigidness), being able to kick ass on TV all while balancing her passion for social justice, and wants us all to know that "PD" isn't just your average cop show.

So, confession: I don't keep up with "Chicago Fire." Does it help to have some familiarity with that show when watching "Chicago PD"?
That's interesting. If you don't watch "Fire," you can absolutely watch "PD" and have no problem picking up the show at all. What I'm finding as a fan of "Fire" is how much fun it is to watch both because you kind of get double ... it's even more than getting double the story, I guess, because theoretically, we're talking about two shows, so you get triple the story. There are all these things happening; our writers are so adept at what they do that you understand who people are when they come from "Fire" onto our show, even if you don't watch it. But if you do, when they come on to our show and we go on to theirs, there's so much more life to it, it's really kind of incredible.

Your scenes in the second episode weren't really "coppy." It actually reminded me of Brooke, kind of emotional, dramatic, so I was watching, thinking, "Um, where's the cop stuff?" But then it all happens later. Is it safe to say the show isn't exactly a procedural?
Yeah, it's definitely not. It's not a procedural. We're not a formulaic show that's about the bad guys that we catch. We're a show that's about a unit made up of very complicated and multi-faceted people that gives us a multi-layered show about human beings who're in extreme situations. If you love cop shows and procedurals, this stands a chance to be your favourite one, because you get all of that stuff but you get it with storylines that feel like cable shows. And the action, it feels like it comes out of movies.

And all these things that I'm saying are things that I've actually been told through feedback about the show from some of the toughest critics that I know. I've asked people that don't pull punches to tell me what they think and I'm really inclined to agree with them. It's not just a show about these people who go and catch this bad guy on this day. There's so much inner life and complexity to these characters, to learning about why they're motivated to do what they're doing, and why they care about these things and it feels like it has so much more depth and it makes it all feel so important and tense.

That's good because people like tense. People like to be on the edge of their seats.
Yeah, we're a high-tension wire. I've been thinking about it and our show is a pot that's just boiling over all the time. You could turn it down, but we don't turn it down very often.

Erin has a mysterious past. Well, the entire unit seems to have secrets. How soon will that all roll out? Will we learn about everyone right away, or will that be a gradual thing?
It's gradual. One of the things I really appreciate about our writing team is, the same way we don't wrap up something in a bow at the end of an episode, we don't just dump all the information. Things come out in fits and starts and by the time we get to Episode 6, Halstead (Jesse Lee Soffer), who's Erin's partner, gets to find out a little bit of why she's so close to Voight but he still knows nothing about how she got there. He knows about once she got there but he doesn't know anything about how she got there. And I really appreciate that. You'll get snippets of it and it all continues to build.

As an actor, do you know what your character is all about or are you filling in some blanks as you see fit?
It's a balance. That's a constant dance when you're working on something. There's a lot that I know, there's a lot that I've chosen to fill in. Recently, I was having a conversation with one of the writers and said, "These are the things that I've put into my mind for her," and he looked at me and asked if I had talked to our showrunner about this. I said no, and he goes, "Because what you just said to me is exactly what you're going to find out in the next episode and that's weird." And I went, 'Well, obviously we're all doing something right here.' Intuitively, we really get each other. That's a very exciting place to be.

It is an exciting place to be, you can't make up chemistry. You can see it, everyone jives.
Oh, God, we do. We have so much chemistry, it's crazy.

Will things be getting romantic for Erin anytime soon? If it's anything like "Chicago Fire," I've seen the ads. There's a lot of sexy time going on over there...
Human nature is to fall in love, fall in lust, crave physical touch, all of that, really. So I think those things will exist for us. They don't exist for us as much as it exists on "Fire." Not to say that it won't. We're just doing so much mad action right now. Let's be real, we're a group of young people in very intense situations, emotions run very high but at the same time, Erin's not great at letting people in so we'll see how that affects her, what could be her romantic life.

What are the action scenes like and how have the people of Chicago been with you guys running around their streets, chasing pretend bad guys?
Oh, amazing. Amazing. I'm so enamoured with this city just because of this rich life that it has, the incredible food culture and the dichotomy of all the good and bad of it. And then you get to know people who live here, who are so welcoming and just so damn cool, and who are excited that we're here, that we're bringing so much industry and so much money into the city. They're really nice people who will show up and watch a scene go down and go, "Hey, that was really friggin' cool," and "We're glad you're here and you're showing people Chicago." That's just so awesome to have everybody here be glad that we're here.

What's it like holding a gun, and holding it convincingly? Because you hold it convincingly. Some ... don't.
I've been a marksman shooter since I was 12 years old...

So it's great then? [Laughs]
Yeah. For me, it's a ball. I'm a big advocate of gun safety and learning to properly use them and it's a pleasure for us to show people basically how it's done. And not messing around, being all, it's so cool, look at us. It's not making it glamorous. It's a job. It's tough and it's scary and it's dangerous and it's nice being able to be real about all of that.

I'm sure you've been asked a zillion times what it's like playing a cop but, honestly, Erin is just so different from your previous roles. How has it been, transitioning into a bad girl of a different kind?
Well, for me, the way that I look at is, without giving away who Erin is: I've definitely been in this position where I've seen a guy in a bar grab a girl inappropriately, freak her out and I've gotten in the middle of it. And Erin's the one who would get in the middle of it, not by going up and saying, 'What the f**k do you think you're doing?" She'd go up and crack him in the face. Imagine her going from being a girl who's a brawler defending somebody who needs it, to a woman who gets tactically trained to defuse situations who then goes and defends people who need it in places where no one is going to help them? She has to not be such a hot-head, but still she's using that streak in her of being feisty and a bad-ass to service the greater good.

That must be a dream to play.
Yeah, it's the best. I spend all my free time on the Internet and on social channels working on social justice projects. For now my job actually pays me in all my time at work ... to work on talking about why social justice is so important, why people need help and why we should care about strangers. It's pretty much the dream job for me.

You often use Twitter, Facebook, and your blog to raise awareness of world events, political issues, things you are passionate about. Would you ever want to make a career out of that, work in politics?
You know, I don't know yet. I've thought about it. At the same time, a little bit like my character, I think I would just want to smack everybody for being so slow-moving and preposterous so I don't know. [Laughs] I don't know. We'll have to see how the years go, I suppose.

Not including your co-stars, of course, so I'll give you an out there, but who is your favourite person that you follow on Twitter?
Oh my God, really? Hmm ... My favourite account that I follow on Twitter is RYOT News. They're reporting like human beings, not like news reporters, on what's happening all over the world, all the time, but at the end of every news story, there's a course of action to take. So you can click to sign a petition, you can click and call a senator, you can donate to a cause, so it makes all the crazy things going on in the world not feel so insurmountable and it makes readers not feel helpless. And that's the coolest thing because who doesn't get depressed when they watch the evening news? And now you can say, you know what, I don't like that and I'm going to do something about it. Or I think what these people are doing is so amazing and I want to support them. That, I think, is just the coolest.

"Chicago PD" premieres Wednesday, Jan. 8 at 8 p.m. EST on Global and 10 p.m. EST on NBC. (It returns to its normal timeslot of Wednesdays at 10 next week on Global.)

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  • "Ironside"

    In the gritty world of the NYPD, no one’s tougher than Det. Robert Ironside (Blair Underwood, “The Event,” “In Treatment”). He’s a fearless cop who won’t stop until the guilty are brought to justice. He and his trusted, handpicked team of specialists — Virgil (Pablo Schreiber, “The Wire” “Lights Out”), Holly (Spencer Grammer, “Greek,” “As the World Turns”) and Teddy (Neal Bledsoe, “Smash,” “Ugly Betty”), as well as his former partner Gary (Brent Sexton, “The Killing”) and boss, Det. Ed Rollins (Kenneth Choi, “Sons of Anarchy”) — will do whatever it takes to solve New York’s most difficult and notorious crimes. As a detective, Ironside’s instincts are second to none, and those around him have to stay on their toes if they want to keep up because when his spine was shattered by a bullet two years ago, Ironside swore he’d never let a wheelchair slow him down.

  • "Ironside"

  • "Ironside"

  • "Ironside"

  • "The Michael J. Fox Show"

    Look who’s making the news again. One of New York’s most beloved news anchors, Mike Henry (Michael J. Fox, “Spin City,” “Family Ties”), put his career on hold to spend more time with his family and focus on his health after he was diagnosed with Parkinson’s disease. But five years later, with the kids busy growing up and Mike growing restless, it just might be time for him to get back to work. Having never wanted Mike to leave in the first place, his old boss Harris Green (Wendell Pierce, “The Wire,” “Treme”) jumped at the chance to get him back on TV. The trick, as it’s always been, was to make Mike think it was his idea. Now the plan is in motion and Mike will be back to juggling home, family, and career — just like the old days, but only better.

  • "The Michael J. Fox Show"

  • "The Michael J. Fox Show"

  • "The Michael J. Fox Show"

  • "Sean Saves the Word"

    Sean (Sean P. Hayes, “Will & Grace”) is a divorced gay dad who juggles a lot — his successful but demanding career, offbeat employees, pushy mom Lorna (Linda Lavin, “Alice”) and weekends with his teenage daughter, Ellie (Sami Isler). So when she moves in full-time, it’s a whole new world. Never one to do anything halfway, Sean’s intent on being the best dad ever, so he loads up on parenting how-to books and plans Pinterest-worthy family dinners. But it seems his company’s new owner has decided Sean and his team should work longer hours, putting a damper on his homemaking plans and throwing a kink in Sean’s perfectly constructed work/life balance. Ellie sees this development as a plus. She loves her dad, but he’s clearly going overboard. From keeping his boss happy, employees motivated and enduring his mother’s tactless “advice” to raising a smart, grounded and healthy kid, it’s going to be a growing experience, to say the least. But if anyone can handle it all, it’s Sean. Thomas Lennon (“Reno 911”), Lindsay Sloane (“Weeds”) and Echo Kellum (“Ben and Kate”) also star.

  • "Sean Saves The World"

  • "Sean Saves The World"

  • "Sean Saves The World"

  • "The Blacklist"

    For decades, ex-government agent Raymond “Red” Reddington (James Spader, “The Office,” “Boston Legal”) has been one of the FBI’s Most Wanted fugitives. Brokering shadowy deals for criminals across the globe, Red was known by many as “The Concierge of Crime.” Now, he’s mysteriously surrendered to the FBI with an explosive offer: He will help catch a long-thought-dead terrorist, Ranko Zamani, under the condition that he speaks only to Elizabeth “Liz” Keen (Megan Boone, “Law & Order: Los Angeles”), an FBI profiler fresh out of Quantico. For Liz, it’s going to be one hell of a first day on the job. What follows is a twisting series of events as the race to stop a terrorist begins. What are Red’s true intentions? Why has he chosen Liz, a woman with whom he seemingly has no connection? Does Liz have secrets of her own? Zamani is only the first of many on a list that Red has compiled over the years: a “blacklist” of politicians, mobsters, spies and international terrorists. He will help catch them all… with the caveat that Liz continues to work as his partner. Red will teach Liz to think like a criminal and “see the bigger picture”… whether she wants to or not. “The Blacklist” also stars are Diego Klattenhoff (“Homeland”), Harry Lennix (“Man of Steel”), Ryan Eggold (“90210”) and Ilfenesh Hadera (“Da Brick”).

  • "The Blacklist"

  • "The Blacklist"

  • "The Blacklist"

  • "Dracula"

    Golden Globe winner Jonathan Rhys Meyers (“The Tudors”) stars in this provocative new drama as one of the world’s most iconic characters. It’s the late 19th century and the mysterious Dracula (Rhys Meyers) has arrived in London, posing as an American entrepreneur who wants to bring modern science to Victorian society. He’s especially interested in the new technology of electricity, which promises to brighten the night — useful for someone who avoids the sun. But he has another reason for his travels: He hopes to take revenge on those who cursed him with immortality centuries earlier. Everything seems to be going according to plan… until he becomes infatuated with a woman who appears to be a reincarnation of his dead wife. Victoria Smurfit (“About a Boy”), Thomas Kretschmann (“King Kong”), Jessica De Gouw (“Arrow”), Oliver Jackson-Cohen (“Mr. Selfridge”), Nonso Anozie (“Game of Thrones”) and Katie McGrath (“Merlin”) also star.

  • "Dracula"

  • "Dracula"

  • "Dracula"

  • "Welcome to the Family"

    Parents Dan Yoder (Mike O’Malley, “Glee,” “My Name Is Earl”) and wife Karina (Mary McCormack, “In Plain Sight,” “The West Wing”) find out on the day their daughter Molly (Ella Rae Peck (“Deception,” “Gossip Girl”) is graduating from high school with an acceptance to college, she announces she pregnant. Across town in East L.A., Junior Hernandez (Joseph Haro, “Glee,” “Awkward”), in the middle of his high school valedictorian speech, gets a text from girlfriend Molly that he’s going to be a daddy. Expectedly, Junior’s parents Miguel (Ricardo Chavira, “Desperate Housewives”) and Lisette (Justina Machado, “Six Feet Under,” “ER”) are also upset, as they now have Caucasians in the family. What follows is a crash course in culture blending as Molly and Junior decide they want to get married and, in doing so, bring together two very different families. The dads have the most difficult time reconciling while the moms take a softer approach to get to know one another. When the parents fully realize that their kids are serious about making a life together, the adults exhale and begin to come to terms with this new blended family and start to understand it will take, humor, love and tolerance to make it all work.

  • "Welcome to the Family"

  • "Welcome to the Family"

  • "Welcome to the Family"

  • "Undateable"

    When confident slacker Danny Beeman (Chris D’Elia, “Whitney,” “Glory Daze”) takes Justin (comedian Brent Morin) on as a roommate, Danny unwittingly inherits Justin’s group of romantically challenged friends. Seeing himself as the ultimate player, Danny decides to teach the crew (who he dubs “The Undateables”) everything he knows about “the game of love.” For their first lesson, Danny takes the guys to an event hosted by his sister, Leslie (Bianca Kajlich, “Rules of Engagement”), who is a single mom with dating difficulties of her own. At first, Danny’s advice seems to pay off big-time: The shy guy talks to a girl, the no-filter dude learns it’s never OK to ask a woman when she’s due, and his nebbish roommate, Justin, goes home with a mystery woman. It’s not until the next day that they figure out it was Leslie. Here’s a refreshing comedy about the “do’s,” “don’ts” and “duhs” of dating.

  • "Crisis"

    It’s field trip day for the students of Ballard High School, a place that educates the children of Washington, D.C.’s elite, top-of-their-industry CEOs, international diplomats, political power players and even the president’s son. But when their bus is ambushed on a secluded rural road, the teenagers and their chaperones are taken, igniting a national crisis. Now with some of the country’s most powerful parents at the mercy of one vengeful mastermind, the question arises: How far would you go and what would you become to ensure your child’s safe return? With so many parents and dignitaries put into play with nowhere to turn and no one to trust, this unthinkable scenario grows from the select families at risk to an entire nation at stake.

  • "Believe"

    Levitation, telekinesis, the ability to control nature and even predict the future… Since she was 2 years old, Bo (Johnny Sequoyah) has had gifts she could neither fully understand, nor control. Raised by a small group known as the “True Believers,” the orphaned girl has been safeguarded from harmful outsiders who would use her forces for personal gain. But now that she is 10, her powers have become stronger and the threat has grown more dangerous. With her life and future now in jeopardy, the “Believers” turn to the only person they see fit to be her full-time protector. That is, once they break him out of jail. Tate (Jake McLaughlin), a wrongfully imprisoned death row inmate who’s lost his will, is initially reluctant until he witnesses one of her extraordinary abilities. Bo sees people for who they truly are… and who they may become. Tate and Bo begin their journey, one in which trust must be earned. Traveling from city to city, every place they stop and everyone they meet will be changed forever. But they’ll have to keep going to stay one step ahead of the sinister forces after Bo’s power… because it will take a miracle to keep them safe forever. “Believe” also stars Delroy Lindo and Kyle MacLachlan.

  • "The Family Guide"

    It’s not every family that’s brought closer together by divorce, but then again, the Fishers aren’t exactly typical. Take Mel Fisher (J.K. Simmons, “The Closer,” “Law & Order”), for example. Whether it’s chopping down trees, showing his daughter how to drive or playing football with his son, he’s never let the fact that he’s blind slow him down. Then there’s Joyce Fisher (Parker Posey, “Louie,” “For Your Consideration”), possibly the only mom in Pasadena to smoke a pipe. For her, divorce is like a second coming of age, a chance to be the teen she never was. Just ask ‘80s-obsessed teenage daughter Katie (Ava Deluca-Verley, “Southland”), whose clothes Joyce is always borrowing. At the center of all this is Henry (Eli Baker), the Fisher’s 11-year old son. Having always been his dad’s eyes, ears and wingman, Henry’s less than thrilled when Mel shows up with Elvis, a guide dog… which is also how Henry learns about the pending divorce. While reluctant to the changes this dog would bring, it’s through the adult Henry’s voice-over (Jason Bateman, “Arrested Development”) that we find out his parent’s split would “allow all of us to finally discover who we needed to be.”

  • "About A Boy"

    Based on the best-selling Nick Hornby (“High Fidelity,” “An Education”) novel, writer Jason Katims (“Friday Night Lights,” “Parenthood”) and director Jon Favreau (“Iron Man,” “Revolution”) present a different kind of coming-of-age story. Will Freeman (David Walton, “Bent,” “Perfect Couples”) lives a charmed existence as the ultimate man-child. After writing a hit song, he was granted a life of free time, free love and freedom from financial woes. He’s single, unemployed and loving it. So imagine his surprise when Fiona (Minnie Driver, “Good Will Hunting,” “Barney’s Version”), a needy single mom and her oddly charming 11-year-old son, Marcus (Benjamin Stockham, “1600 Penn”), move in next door and disrupt his perfect world. When Marcus begins dropping by his home unannounced, Will’s not so sure about being a kid’s new best friend, until, of course, Will discovers that women find single dads irresistible. That changes everything and a deal is struck: Marcus will pretend to be Will’s son and, in return, Marcus is allowed to chill at Will’s house. Before he realizes it, Will starts to enjoy the visits and even finds himself looking out for the kid. In fact, this newfound friendship may very well teach him a thing or two that he never imagined possible — about himself and caring for others.

  • "Chicago PD"

    District 21 of the Chicago Police Department is made up of two distinctly different groups: The uniformed cops who patrol the beat and deal with street crimes, and the intelligence unit, the team that combats the city’s major offenses, such as organized crime, drug trafficking and high-profile murders. Leading the intelligence team is Sgt. Hank Voight (Jason Beghe), a man not against skirting the law in the pursuit of justice. Demanding and tough, only those who can take the heat survive under Voight’s command. Take Det. Antonio Dawson (Jon Seda), for example. Despite a troubled history with his boss, Dawson has ambitions of running the unit. If that means facing off against Voight every day, he’ll persevere. From the street cops with dreams of moving up to the elite crew who are already in, “life on the job” is a daily challenge.

  • "The Night Shift"

    Welcome to the night shift, where every day is a fight between the heroic efforts of saving lives and the hard truths of running a hospital. At San Antonio Memorial, the men and women who work the wee hours are a special breed, particularly adrenaline junkie T.C. Callahan (Eoin Macken, “Merlin”). After a grueling tour of duty in the Middle East, T.C. is about to learn that his toughest battles will be fought right at home. He and his irreverent team of late-night docs, including Topher (Ken Leung, “Lost”) and Drew (Brendan Fehr, “Roswell”), know how to let off steam with the casual prank or two, but when lives are at stake they are all business. Unfortunately, the night shift is now under new management and boss Michael Ragosa (Freddy Rodriguez, “Six Feet Under”) is more interested in cutting costs than helping people. But T.C. has never met a rule he couldn’t break, or a person he won’t stand up to. And it’s clear that not even his ex-girlfriend (Jill Flint, “The Good Wife”) who is a doctor and now Ragosa’s second in charge, has a chance at keeping him in line. If Ragosa wants a war, he’ll get one.