Singer-actress Mandy Moore says the upcoming season of "This Is Us" will explore new and exciting themes.

Moore essays the role of Rebecca Pearson in the hit show.

"I think Rebecca and her being needed is a really exciting feeling. It's a new feeling -- in terms of their relationships with one another especially as adults," Moore said.

Rebecca is the matriarch of Pearson family in the series that goes back and forth between past and present in the lives of the extended Pearson family. The show will be back with fourth season on September 25 on Hotstar Premium in India. The third season ended with Rebecca seen as a frail and bedridden old woman.

Talking about the upcoming season, Isaac Aptaker, executive producer, said: "We're going to be doing a lot with Rebecca in Season 4. We're going to be diving back into all our time periods. We're going to see what happens next with Rebecca and The Big Three after high school. We're always diving back to the 1970s, it's such a fun period -- the music the clothes, it so romantic and such a nice contrast to the sadder part of the Rebecca's life."

In the series, Moore is seen with Milo Ventimiglia who plays her husband Jack and their three children are played as adults by Chrissy Metz, Justin Hartley, and Sterling K. Brown.