Everything is on the line for Wallace Boden (Eamonn Walker) on Tuesday's winter finale of Chicago Fire.

After his arrest at the end of last week's episode, Boden needs to prove that he was set up by corrupt real estate developer Roger Maddox (Mark Hengst) for assaulting his neighbor, if he has any hope of salvaging his reputation, his job and his marriage.

"Boden is seemingly being attacked, and trying to keep his house together," Walker tells TVGuide.com. "The stakes are very, very high. ... For four years, we've been following this man. He and his lieutenants always have the answers, always light the way. And he really doesn't know how to get through this. At the end of the day, on the other side of the blast out, after all of his brainstorming, he doesn't have the answer."

In Boden's absence, Patterson (Brian White) steps in as interim chief and learns a few harsh lessons of his own as he continues to try to win over the 51 crew.

TVGuide.com chatted with Walker about Boden's story line and how much of a ripple effect his arrest will have on the rest of the season.

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We saw in last week's episode that the charges against Boden are starting to take a toll. Aside from his arrest, what are these accusations doing to him on a personal level?
Eamonn Walker:
He's in a slow meltdown. Boden is the lowest he's ever been. ... And he gets to the point where he says, "I'm going to protect my family now." This is a personal thing. You get to see this man at his most vulnerable. He can't come through this on his own. He needs the firehouse family to [rely] upon, and he needs his wife.

How much of a strain does this put on his marriage?
Walker:
There are problems at home. ... You saw in last week's episode that it put a strain on the marriage and the relationship. He's acting out, because he's under pressure and he's stressed. Normally when we're stressed, the first place you let it manifest is within the home and the people who supposedly love you, because they're supposed to love you no matter what. But they can only take so much. So the first place it came out was at the wife, and she said, "I don't know if I can do this anymore." And that put the fear of God in Boden. That made him decide that he didn't care who he faced, because he's not willing to lose his family, his wife or his child.

Is that what caused him to confront Maddox in last week's episode?
Walker:
Boden went straight into his office and faced him because he needed to know where he stood and who he was, and as a man and an animal on the planet was like, now I know who to face. Everybody else can just get out the way, and it's me and my family and my job on the line, and I've got decisions to make. It was great to be able to play that part and not have to always be the man in control.

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Patterson's transition hasn't been a smooth one thus far. Does him replacing Boden create more tension?
Walker:
Patterson is the real way forward for the fire department, dealing much more with the politics of the city, and Boden is old-school. Boden is a man who just wants to help people as best he can. And he uses every single bit of knowledge that he has to be able to do that, and the politics way is not his way. Patterson has tried to teach him that, and the frustration that comes up between two friends who play cards together has created a void in their relationship. But in the end, Patterson has got stuff to learn from Boden too, because he's not really a people person.

There was a line in last week's episode where Boden tells Patterson he needs to stop riding the fence. Does this give him an opportunity to win some of the crew over?
Walker:
You have to earn your respect, wherever you go. But he's dancing with the devil, so to speak, and he's an ambitious fellow, so he's got his own demons which he's facing within. ... At one point, he said, "I don't mind if you don't like me. You have to respect the job." That's where they all come from, but there's a difference in interpretation of respecting the job. Patterson is not the enemy. Right now it looks like Riddle is the enemy. But the real enemy showed his face last week.

Will this story line continue to play out beyond the winter finale?
Walker:
There will be a resolution at the end of the night. ... We got used to Boden being the top of the food chain - although he wasn't, because the hierarchy was obviously in place But this [teaches] him a lesson to rely on his friends and his fellow firefighters much more. How it will actually manifest is, I think, is it's still a great team of people, full of mavericks who come up with wonderful ideas of how to get through any difficult situation. But I think what's going to happen is it's going to convince [Boden] that he was right, that you need a family atmosphere.

Chicago Fire airs Tuesdays at 10/9c on NBC.