Chicago PD: The Thin Blue Line, Unfiltered.

Ruzek (Patrick Flueger) has been through a lot of traumatizing stuff, but watching his friend get shot right in front of him has to be one of the biggest moments yet. Seeing Martel (Victoria Cartagena) lying on the asphalt like a common criminal in the Chicago P.D. Season 12 premiere awoke something in Ruzek. It was as shocking as it was unnerving. In Chicago P.D. Season 12, Episode 2, “Blood Bleeds Blue,” Ruzek aims to bring Martel’s killer to justice and will do anything to catch them. The hunt brings him and Chicago P.D.‘s latest addition, Kiana Cook (Toya Turner) together, and they embark on a manhunt with the rest of Intelligence in tow. The official logline for the episode reads:

“After tragedy strikes Intelligence, the unit must persevere during an adrenalized manhunt across the city.”

The promo begins with Ruzek at the scene where Martel was murdered. He holds her seemingly lifeless body while covering himself to avoid meeting the same fate. Patrol Officer Cook joins in the search for the killer when they go on the run. A bad situation worsens when the killer kidnaps a child. “That man shot my friend; now he has a two-year-old child,” Ruzek says in the video. It teases high-octane action scenes with shootouts and explosions in the upcoming episode. But the eagle-eyed Voight realizes that Ruzek is not after justice but revenge and warns him about it. Showrunner Gwen Sigan previously teased to TV Insider this adrenaline-fueled Ruzek episode, saying:

“Episode 2 is really just an adrenaline ride, and I think you’re in the shock the whole episode. Our hope was that you almost as an audience member feel the same anxiety that Ruzek’s feeling. It’s a real-time episode, so you’re like 42 minutes of being in that moment with Ruzek and feeling what it feels like to have just seen that happen.”

What Is Ahead in ‘Chicago P.D.’ Season 12?

The episode also ties into the arcs the show will explore this season. Martel’s death “felt thematically like the perfect story and that it would also trigger all the themes we want to tell this year, which are kind of identity and self and crisis of self and transformation and all these things that you think about a lot when you’re thinking about your own mortality.”

In her first episode, the show throws Cook into the middle of the frenzy, which will continue as she becomes familiar with the team. “We’ve got a really fun one for Cook, one of her first episodes with us. Episode 5 is a really just a weird one. It’s Cook and Torres, and we get to see the pair of them really develop this fun, interesting relationship together. I think they just can see each other and understand each other pretty instantaneously, which is fun. That’s always a great dynamic with somebody, and they have trust pretty quickly with each other. That has an interesting murder mystery vibe to it,” Sigan teased.

Watch Ruzek’s adrenaline-filled episode and Cook’s debut on Wednesday, October 2, on NBC.