'This Is Us' Showrunners Promise 'Hopeful' Season 3

After a second season clouded by the grief of Jack Pearson's death, This Is Us is gearing up for a lighter, more "hopeful" season three.

The last time we saw the Pearson clan during the season 2 finale, Kate (Chrissy Metz) and Toby (Chris Sullivan) tied the knot as flashes of the family's future saw the couple dealing with Toby's depression, Kevin (Justin Hartley) headed to Vietnam to learn more about his late father, and future Randall (Sterling K. Brown) and his daughter Tess' (Iantha Richardson) relationship.

"We felt like at the end of Season 2 our family had grieved and processed the loss of Jack at a deeper level than they ever had before, so I think this is a hopeful season, and it's a season about new beginnings for everybody," co-showrunner Elizabeth Berger said at the Television Critics Association press tour panel for the show Wednesday, Variety reports.

Season three, which will consist of 18 episodes, will start with the Big Three's 38th birthday, executive producer Isaac Aptaker teased. He added that although the "audience will go with us" as they "break all of the rules," regarding timeline, starting every season on a new birthday "grounds everyone."

A lot of where the third season will go was "teased" with the second season finale flash forward, including Kevin exploring his dad Jack's (Milo Ventimiglia) early life.

The series also brought in real-life veteran and author Tim O'Brien as a consultant to "really get the story right." Aptaker shared O'Brien will actually be co-writing with Dan Fogelman "an early episode that really dives into Jack's life" at war.

Berger added that it's "freeing" to move beyond Jack's death and "get to tell a whole different type of story."

"To all of a sudden be immersed in the Vietnam war, we think is really significant," she said.

Aptaker added that looking at older Randall and his daughter's relationship is part of a "bigger plan for the series," which means fans won't get all the answers in season three.

The storyline will allow them to "jump to decades we've never gone to before" and "play with the storytelling format."

"What's so cool about the style of our show is we can keep growing and expanding out in time," he said. "We've really only spent 36 hours with [the characters] and there's so much more" to explore.

This Is Us will return for its third season Tuesday, September 25 at 9 p.m. ET on NBC.