LOS ANGELES, Jan. 14 (UPI) -- This Is Us returns Tuesday to begin resolving the new drama launched by the fall finale cliffhanger.
The last episode revealed that at some point in the future, Randall (Sterling K. Brown) and Kevin (Justin Hartley) stop speaking. Before that, Randall worries about his mother Rebecca (Mandy Moore) becoming forgetful and evasive.
Cast members Brown, Moore and Chris Sullivan and show creator Dan Fogelman were on a Television Critics Association panel recently to discuss where the show is headed.
Brown said Randall continues to struggle with anxiety issues that lead to the conflicts hinted at in the fall finale.
"Fogelman and our writers came up with a storyline that I think is quite compelling," Brown said. "It allows us to sort of delve further into Randall's mental health and how he takes care of himself. What's right and what's wrong about how he takes care of himself and how he could possibly do a better job at that."
Brown also told This Is Us viewers to expect another shocking revelation at the end of Tuesday's episode.
"Then, like, this moment happens where you're like, 'Oh. Oh, [expletive]. This is about to kind of go a little sideways,'" Brown said.
Flash forwards also revealed that Randall's mother's forgetfulness could be more serious than forgetting her phone or getting lost in town. She confessed to Randall that she went to a movie and forgot what she was there to see.
This Is Us has not revealed Rebecca's diagnosis yet, but Moore knows the mystery ailment.
"It's something that I have done a lot of research on and something I've paid a careful amount of attention to," Moore said. "I want to thoughtfully approach what Rebecca is sort of going through at this stage in her life with as much care and consideration. I can't imagine being in that position."
Moore feels it's too soon to reveal what exactly Rebecca is experiencing. She said This Is Us will uncover it as Rebecca finds out.
"I don't want to speak too much to it, because obviously, I want people to watch the season unfold and [go on] this journey that she's on with her family," Moore said.
Also in the fall finale, Randall and Beth Watson's adopted daughter, Deja (Lyric Ross), invited her mother to Christmas dinner. Beth and Randall fostered Deja and eventually adopted her. If her biological mother is now stable, Beth and Randall wonder if Deja still needs them for stability.
They also feel guilty feeling competitive with Deja's mother. Watson said Beth is able to focus on the foundation that she and Randall gave Deja, regardless of what comes next.
"I'm just grateful she is 18, and she's going to be out of the nest and finding her way in the world," Watson said. "We can be the people who set her up for that and then let her have her wings to fly. Her former years are already set. She was in another household, and that's what that is. But we have a chance to set her up for something greater."
In Kate (Chrissy Metz) and Toby's (Sullivan) story, their marriage is becoming strained. They have parental stress dealing with a blind infant. Even more friction comes from Toby's sudden weight loss.
Sullivan revealed his physique in a shirtless scene on This Is Us. It was a surprise to Kate because he wouldn't tell her he was going to the gym.
"I just got too ripped," Sullivan joked.
The actor appreciated the complexity of his Season 4 story. On the surface, getting in shape should be a positive change for Toby. On This Is Us, it's more complicated than that.
"Even things that can be perceived as healthy can find their way to be detrimental if they're not approached in a conscious fashion," Sullivan said.
This is Us is renewed through Season 6, at which point Fogelman says the show will end.
It continues to introduce new threads, like Kate and Toby's grown-up son, Rebecca's deteriorating health and a forthcoming feud between Randall and Kevin. As epic as the Pearson family becomes, Fogelman says it is driving to an intimate conclusion.
"As we wind the show down eventually, it becomes in a strange way kind of much like the pilot was, which is just a very intimate story of this family," Fogelman said. "When we're able to just kind of sit inside of ourselves and also find propulsive ways to keep the audience excited and invested, that's when we're hitting our sweet spot, I think."
This Is Us airs Tuesdays at 9 p.m. on NBC.