The new year and, specifically, the 100th episode of Parenthood brought a lot of tough decisions for the Braverman clan. Following his sudden hospitalization, Zeek (Craig T. Nelson) must decide whether to have another open-heart surgery. Sarah (Lauren Graham) will have to give Hank (Ray Romano) an answer to his surprise proposal. Adam (Peter Krause) and Crosby (Dax Shepard) must settle on The Luncheonette's future, or lack thereof, after the break-in. And Julia (Erika Christensen) and Joel (Sam Jaeger) still have to figure out whether their one-night reconciliation will become more permanent.

"That episode launches the final crescendo, the final movement of the whole series," showrunner Jason Katims tells TVGuide.com of Parenthood's final three episodes (Thursdays, 10/9c, NBC). "There's going to be stories that we've led to over the season or in some cases over a couple of seasons and in some cases, over the whole series."

Zeek's battle will loom large over the rest of the clan during the last three episodes. "That's designed as a way of putting a lot of characters at crossroads in their lives," Katims says. "[They're] having to make those decisions at a time when their decisions are in a large way being informed by what's going on with Zeek and the fact that they're being faced with the reality that life is short. I think that lends an added poignancy to the decisions that they are making."

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So just how will the members of our favorite TV family make up their minds? And what is in store for the series finale? Read on for more scoop:

Zeek has been battling health issues all season, so why present him with this kind of decision? Jason Katims: One of the things that I think is wrenching about going through such a serious health crisis in a family is the uncertainty about what to do. When you're faced with a decision where there's not necessarily a right or wrong answer, those moments were really challenging, and so that's why we decided to take that path.

He said he didn't want to get the kids involved, but how will they react to that and deal with this decision he has to make in the last episodes? Katims: What's happening with Zeek is certainly informing a lot of what happens. Especially the adult siblings, but everybody in the family - it's affecting their decisions and what they're doing. But they also have stories of an urgent-enough nature that they're also simultaneously dealing with those things. We wanted to do in the end of the series what we have done throughout the show, which is have a lot of balls in the air. And so while the decision about Zeek is obviously a big one, a lot of it is dealt with more privately between Zeek and Camille and doesn't necessarily become a big storyline in the last couple of episodes. It's not like there's a scene with all of the siblings sitting with Zeek and Camille doing an intervention or something like that.

Sarah has a big decision to make with Hank. How is she going to approach it? Katims: That's a very good question. It's a lot of what happens in the next episode coming up. She doesn't know what to do, so she talks to Hank about it and she talks to people who are big influences in her life, like Julia and her mom.

Sarah and Hank have been together for a long time, and we've also seen a lot of Hank's family this season, so should we assume they're headed for a happy ending? Katims: I think she's definitely at a crossroads in her life and she needs to decide. [For her,] these next few episodes are all about: What is a happy ending for me?... That is definitely dealt with and she makes a decision in the next episode.

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And then there's the issue with The Luncheonette and Adam and Crosby wanting two different things. How will they figure out what to do? Katims: I feel like the reason why that storyline is moving to me is it's really such a joy to watch those two brothers work together and how they built this really unique business. So in a way you're really rooting for them to resolve this and to figure out a way to compromise, but I think what makes the story interesting is it's not really what's best for Adam. What's best for Adam is maybe not to make this compromise. I think it puts Adam in a place where he's choosing between what's right for him and what the best thing is for his brother and his extended family. When we started the show, much of the first season or two was focused on Adam being the person who felt the weight of the world on his shoulders. He had the role in the family where everyone would come to him, and he welcomed that role. He didn't really resent it, but it did affect him. And now I feel like we've come full circle at the end.

Clearly, Crosby wants to stay and try to make this business work even if the chances are not great that it's going to work. He has no conflict there. But I think the conflict comes from Adam. Over the next couple of episodes, we're going to see him having to choose between what's best for his brother and his family and what's best for himself and his immediate family.

What can you tease specifically about the series finale? What do you hope viewers will take away from that last episode? Katims: We really wanted to give the show an ending that, first of all, satisfied and answered all of the questions that have been set up through the season and particularly starting in the 100th episode. I think that the episode does answer all of those questions, but I think that beyond that the episode is also a way of really honoring the whole series. There are callbacks in the episode to things we've seen from the very beginning of the show. Baseball, for example, plays a role in the final episode and that was something that we saw in the pilot and then later throughout the first couple of seasons, when Max was playing baseball and Drew played baseball and later, once Victor came into the family, baseball became his way into that family in a way, so we call back to that. It's also a big episode that has lots of scenes of the entire family together, more so than what's usual, kind of like the 100th episode.

Parenthood airs Thursdays at 10/9c on NBC.

Unleashing the fever! Watch Parenthood's best Braverman dance parties: