“There’s a lot that transpires in the last three episodes of the season," Brown told ET while promoting his team-up with Clorox and Thrive Collective, a non-profit focused on providing arts and mentoring programs for at-risk youth. "We go to Vegas tonight for Toby and Kate’s joint bachelor-bachelorette party. We have a beautiful standalone episode for episode 17 that I won’t say too much about. And the season finale will answer some questions and, as always, explore new possibilities for where we’re going to be going in season three.”
Brown acknowledged that viewers' emotions may still be raw after learning how Jack died and experiencing the heartbreaking aftermath of the Pearson patriarch's sudden death, but he expects tear ducts to be taking the night off for Tuesday's episode.
"I will say this, if ever there was a joyous episode of This Is Us, tonight may be a more joyous occasion," the 41-year-old actor teased. "I would not be surprised if the people who are accustomed to shedding tears might save a tear or two with tonight's episode."
With most of the Pearson clan in Sin City celebrating the future nuptials of Kate and Toby, Brown hinted there are some hijinks that go on among the group. But how exactly does someone like Randall, a respectable family man, take Vegas?
"He's not a Spearmint Rhino [Gentlemen's Club]-type guy, if that's what you mean, and neither is really anybody else on our show," Brown said with a laugh. "He actually finds himself a bit at odds over the course of the episode. You'll see why."
Fans were pleasantly surprised when, in the final moments of the Super Bowl episode on Feb. 4, the story of the Pearson family jumped forward several decades, revealing a salt-and-peppered Randall and an adult Tess as a social worker.
"There was a lot of talk about it," Brown recalled. "Similar to when we decided to make Mandy [Moore] present-day Rebecca, there was also a conversation as to whether or not we hire another actor to play that part, or whether or not the makeup looks right. They did several makeup tests and the first test took about four hours, then it took about three-and-a-half and then they whittled it down to three."
"But to know that the show had a plan and a grandness of vision to say that we can take this family anywhere as long as we give them something that grounds them to the Pearsons, the possibilities are endless," he said. "To be the first person to enter into that flash-forward world was cool. It was a nice little Easter egg in the Super Bowl episode."
When pressed for specifics on how the future storyline takes shape in context of the show, Brown alluded to some juicy arcs in the works.
"Oh man, I could tell you some stuff, but [creator Dan] Fogelman would be really upset," he said with a renewed excitement. "There's limitless possibility. It's a family drama, but it's told in such a unique format that it allows for us to move it like a blooming onion, if you will, and it's expanding outward and outward. I can't say too much!"
Brown shared his feelings on the fan response to Jack's death, saying there "definitely is a sense of relief" now that that chapter is over.
"I'm very happy that people got a satisfying payoff to something that had a huge build-up," he reflected. "Dan and we as the cast would have been very disappointed if the fans were like, 'Oh that's what happened? I waited all this time for that?' But I think folks actually enjoyed -- if that's the right word -- I think they were satisfied with how it all transpired."
He also praised Moore's soul-crushing performance, calling her work in those episodes -- especially in the hour with Jack's funeral -- "absolutely amazing." "But what happens now, it leaves new questions and new possibilities. And I want to tell you something so bad, but I can't, like I really can't!" Brown said. "But I'll say this, Dan's about coming up with ways to explore new questions that may inspire a similar sort of intrigue."
Brown, who wrapped filming on This Is Us last week, has a busy slate with Marvel's blockbuster Black Panther dominating the box office, his Saturday Night Live hosting debut on March 10 and his upcoming guest spot on Brooklyn Nine-Nine. But he spent his off day on Tuesday in New York City to help promote empathy, compassion and community connection.
"The incentive was being a dad and wanting my kids to grow up to be responsible, kind, resilient citizens of the world," Brown said of his involvement with Clorox and Thrive Collective, and the importance of cleaning. "It turns out, doing these things are taking responsibility for yourself and it helps with your ability to connect with another human being. What's more important than that?"
This Is Us returns Tuesday at 9 p.m. ET/PT on NBC.