Mandy Mooreknows the ending ofThis Is Us,but even she was shocked to learn what happens in season 4.

“There are a few unexpected twists in the information that we find out in episode one of this season that I didn’t see coming,” the actress tells PEOPLE.

Theseason 4 trailerleft more questions than answers as many new faces will impact the Pearson household in past, present and future.

“It’s going to surprise people and it’s satisfying and it does change the game. It changes the world of the show in a way,” teases Moore, who earned her first Emmy nomination for her role as matriarch Rebecca Pearson.

Mandy Moore and Milo Ventimiglia.Frank Micelotta/Twentieth Century Fox Television/PictureGroup/REX/Shutterstock

PaleyFest 2019: 20th Century Fox Television’s ‘This is Us’, Arrivals, Los Angeles, USA - 24 Mar 2019

“Not that I know everything about the show, but you know we kind of have carte blanche to go in the writers’ room and ask questions. It’s sort of likeHomelandin there,” she says. “There’s the dry erase board filled with information and they have like every single episode for the next like two seasons, I think, like sort of starting to be storyboarded out. Maybe not as much for season 5.”

Moore and costars Milo Ventimiglia, Chrissy Metz, Sterling K. Brown and Justin Hartley have learned about the trajectory of the remaining three seasons of the show from co-creator Dan Fogelman.

Maarten de Boer/NBCUniversal

NBC This Is Us

Meanwhile, in the present day, Randall and Beth readjust their lives with their daughters to a new life in Philadelphia for their careers. And a newly single Kevin, who relapsed, looks to further his career with a new movie role.

Season 4 ofThis Is Uspremieres on Sept. 24 at 9 p.m. ET/PT on NBC.

source: people.com