As it turns out, Chicago P.D. wasn't finished putting Kim Burgess (Marina Squerciati) through the ringer. After returning from a sabbatical in the wake of her sister's assault, Wednesday night's episode saw Burgess put herself on the line for a fellow officer in one of the most intense episodes to date.

It all goes down when a van explodes during a street festival and officer Frank Toma (Ben Youcef), who she helped train, turns up missing. Despite the evidence pointing to his involvement, Burgess firmly believes he's innocent — even if the rest of Central Intelligence crew doesn't. Desperate to get to the truth and exonerate him, she finds herself up going against her superiors.

TV Guide caught up with Squerciati to discuss that heart-racing episode including Kim's newfound rage, what it felt like to be the only one who believes Frank's innocence and what's next for the series.

Marina Squerciati, Chicago P.D.Marina Squerciati, Chicago P.D.

What is Kim's frame of mind going into this episode? Was she mentally prepared to take on the stress of the bombing?
Marina Squerciati: I think after a traumatic event, you don't know how you're going to react anymore. [It's] sort of like a recalibration of everything and so when this happens, I think that the rage in her...she's surprised by the rage. There's a scene in the end where I go after Voight and his companion and I think that that surprises her because that [rage] didn't exist in her before her sister got attacked.

We see that a few times in the episode, her almost losing it. Is she fighting against the world?
Squerciati: It's incredibly hard and almost...it's an odd word to use in this context but embarrassing to go out on a limb like that when everyone's telling you you're wrong. And she's also the only female there and I think that doesn't even feel like she's making a choice, that she believes with her whole heart that this person is innocent and she's gonna do what she has to do to prove that. I really respect that and I hope I have enough guts to do that.

There's an intense scene in the episode where Kim is trying to talk Frank out of suicide and she's begging him to put down the gun. What do you remember from filming that?
Squerciati: Our tech advisor put us in touch with an actual hostage negotiator. Basically, what he told me and what I think if you'll notice in that scene...I never get angry or raise my voice. You kind of be this person's friend and remind them of a calmer world. I think trying to keep casual under those circumstances takes a lot of training which Burgess hasn't had to the extent of a hostage negotiator. But I like that I was able to play it in sort of a casual way and not the crazy TV way, that they let us do that the way that cops actually do it.

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At the end of the episode, Burgess goes after corrupt cop Danny Rose and Voight warns her to back off or risk her career. Will she listen? How important is it for her to take him down?
Squerciati: I do think she does listen. I think it ends on a not-- What I like about this season is that nothing ends perfectly. It's not so black and white. In the first episode, I feel like on another TV show, you'll find out at the end that Halstead didn't actually shoot the girl. But in this, and this new way that the show is going, he did shoot a girl and he has to live with that and contend with that because that's what happens in real life. So the fact that she has to sort make this choice that's messy and dirty and not the right choice...she has to live with that. But she puts her career first.

What other issues are you most excited for the show to cover?
Squerciati: I'm just excited that it's messy. I do feel like it's new television in that it's messy and at the end, the cops aren't always right. Chicago is dealing with a lot right now between the cops and the civilians and the idea that the civilians are right, the cops are right and that we're tackling that each episode is really interesting to me. Being right and not messy is not interesting to me.

Denny Woods has come in as the fact of reform and is already shaking things up. What changes can we expect for the Central Intelligence unit?
Squerciati: Big brother is watching. You don't see Voight taking people to the cage anymore. He realizes that there is a camera in the interrogation room. Someone is always watching and you have to know that when you are with the suspect.

This episode was all about terrorism and racial profiling. How did it speak to you and what do you want people to take away from it?
Squerciati: In an age where we're dealing with terrorism, I think it's important, as trite as it sounds, not to racially profile. And here is this young Muslim man who Burgess stands up for and just knows in her heart that he didn't do it. She knows this person and you can't just assume that he did it because he's Muslim. And I'm proud that she goes out on a limb for him.

Chicago P.D. airs Wednesdays at 10/9c on NBC.