Archie Kao and Jason Beghe Archie Kao and Jason Beghe

He may be gone, but Jin definitely won't be forgotten when Chicago P.D. returns for Season 2 this fall.

"It shakes everybody up," showrunner Matt Olmstead tells, "definitely for the next three or four episodes until people can re-galvanize as a family, but people have some hard feelings about how it all goes down."

In the Season 1 finale, the Intelligence Unit's tech and surveillance expert was found dead in the final moments of the episode after being confronted by Voight (Jason Beghe) about his snooping into Voight for internal affairs. Jin (Archie Kao) was last seen rushing out of his office and sending a mysterious flash drive to an unknown recipient. "[Archie] didn't know nor did we. It's one of those things where the story told was headed in that direction in terms of needing to have a cliff-hanger and a big impact of a season finale and also just show the ramifications of that police work and that unit and street level and no one's guaranteed anything," Olmstead says. "It started to kind of gain momentum; like this character can't survive this."

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Jesse Lee Soffer also laments the loss of Kao. "It was intense. We were very close. We knew right away we were going to miss Archie a lot," he says. "That's a hard blow to take, but it made the finale really intense and kind of amazing."

However, it won't take long for the team to piece together the clues surrounding his mysterious death, which Olmstead says will be solved within the first episode. "His murder hasn't been solved yet so you have the team wanting to know what the hell is going on, in particular Halstead, who has never really carried Voight's water. But then you have Lindsay who's loyal and maybe even an apologist for Voight," Olmstead says. "We play the mystery of who killed Jin, and then certainly the ramifications of, once that mystery is solved, how people feel about who did it and why."

Jin's death, as well as Voight's possible connection to it, will divide the unit. "In the first episode, we're going to definitely focus on Jin and what happened, whether Voight is guilty or not," Halstead says. "I think we're going to hopefully wrap it up pretty quick, but we'll figure out what part of the unit is going to stand behind [Voight] and what part is not going to stand behind him. He looks like a shoo-in but we'll see."

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As suspicions about Voight's possible connection to the murder heat up, he will pull those he trusts closer, such as Ruzek (Patrick John Flueger), whom Voight hand-picks to fill in for Jin. "We have some fun with it because we have Voight going to Ruzek, who's right out of the academy and he's like, 'You took all these computer courses, right?' He's like, 'Yeah, OK, you figure it out,'" Olmstead says. "I'm sure he'll screw it up and bring somebody else in, but for now, he just dumps him because Voight has some trust issues in that role especially so he wants someone he knows will not be reporting on him."

Although Ruzek will be less than enthused about his new professional duties, the latest developments in his personal life are a different story. After sharing a kiss with Burgess (Marina Squerciati) midway through Season 1, the two consummated their feelings for each other in a big way in the season finale despite the fact that Burgess was passed over for a promotion because of her dalliance with Ruzek. "It's tough for her because she likes Ruzek a lot, he likes her so they're going to try and maintain a furtive relationship," Olmstead says. "She knows full well what would happen if Voight finds out, but the heart wants what the heart wants. But also she realizes, 'Hey, uniform isn't that bad,' and also, 'If I don't get intelligence here, there's plenty of other departments in Chicago.'"

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Burgess' change of heart about her longstanding desire to join Intelligence will come courtesy of her new enthusiastic partner in uniform, a role which has yet to be cast. "We realized at the end, Burgess wants to get Intelligence, and pining for Intelligence by extension almost makes it look like the uniform is chump work, which we don't want to do," Olmstead says. "There are a lot of guys in uniform who want to stay in uniform because once you get a gold shield or once you're a detective, the politics, the ass-kissing, all the stuff you've got to deal with, but when you're in uniform, you're out in the car, you're gone, there's no boss breathing down your neck so this character really likes the action."

Olmstead says Burgess' new partner will add an important new voice to the team, and to the show. "He was going to be a third generation smelter in Chicago, but he had uncles who had been inhaling copper and nickel. He was scheduled to go down that road until they closed the plant down," Olmstead says. "He also has perspective in his life of, 'I know what hard work is.' He's a guy who really has a bounce in his step and also helps Burgess realize like, yeah ,actually the uniform's a pretty good place to be for however much longer she is going to do it."

The new season of Chicago P.D. kicks off Wednesday, Sept. 24 at 10/9c on NBC. Rewatch the Season 1 finale here.