Erika Christensen and Sam Jaeger

When Sam Jaeger got the chance to step behind the camera for Tuesday's episode of Parenthood (10/9c, NBC), he was excited to collaborate with one member of the ensemble in particular.  "I got to work with Nora. She's a method actress, the one-and-a-half-year-old," he quips to TVGuide.com of the twins playing Adam and Kristina's youngest child. "Really impressive stuff."

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All joking aside, Jaeger — who previously helmed the 2012 road-trip indie Take Me Home — didn't feel the pressure when it came to directing his cast mates. "Being a director for hire is complicated enough because you're trying to fit into a system that's already running and I think because this is the fourth season, everybody knows their position really well," he says. "Thankfully now I know what feels like the show and what doesn't feel like the show."

On top of directing the show for the first time, Jaeger also had a particularly challenge episode to deal with, following the heartbreaking breast-cancer diagnosis Kristina (Monica Potter) received in the final moments of last week's episode. "He had a lot of family scenes to deal with, some big issues to deal with as far as story points and he did extremely well," his TV wife, Erika Christensen, says.

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Those big issues also include the ongoing story line of Jaeger and Christensen's characters, Joel and Julia, efforts to integrate their newly adopted son, Victor, into the Braverman fold. "It's a long struggle trying to make someone who's come from a very difficult past feel like they're really part of a family," Jaeger says. "No matter how loving the parents are, it's a complicated issue. But I think Joel and Julia are pretty determined parents and people."

It's been a rough road to child No. 2 for the couple, who first had their hearts broken in the second season when they tried (unsuccessfully) to have a baby. Season 3 brought on even more heartache when the baby they were supposed to adopt was taken back by his mother. "I don't know if I've ever seen this exact relationship explored on TV," Christensen says. "Just trying to connect to this boy who already has his own personality and his own thoughts and his own way he's used to behaving and just for a parent to say, 'This is my son.' You want to be able to say you love each other and you can't start on day one with that with someone who is a stranger."

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Although Victor is slowly but surely becoming a part of the family, the extra attention Julia has been paying to her new son has come at the cost of her job, something that will be explored deeply in upcoming episodes. "The first season was really about Julia realizing that she's torn between being a great lawyer and a great mother," Jaeger says. "In Season 4, she realizes that 'I just want to be there with my new boy.'"

It seems Julia just can't catch a break. "It's funny to say its fun to explore someone's really rough time, but it is. It's exciting," Christensen says. "The writers have always loved torturing Julia because she is so centered and considers herself centered and put together, so I like it when I torture her."

So will Julia learn how to better balance her family and her cases, or will she walk away from her demanding career? "We're coming to a crossroads for her. I don't know where it's going to go from here. It could really go a lot of different ways."

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Thankfully, she has a supportive husband at home who may have to step it up. "She leans a lot on Joel to really keep it steady and to try to pick up the pieces. And Joel may have to head back to work," Jaeger says. "That's a conversation that they haven't necessarily had in a long time because she's been the breadwinner so to speak so it changes the family dynamic in a big way."

Does this mean Joel must become the new breadwinner of the Graham family? Jaeger says it's a distinct possibility. "He really prides himself on being a really good contractor, and I think he just wants to figure out a way to make sure the family has food on the table," Jaeger says. "If she wants to be home, and he can go back to doing that, so be it."

Parenthood airs Tuesdays at 10/9c on NBC.

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