This Is Us set on lockdown to prevent story line leaks

The stars of TV drama This Is Us have been hit with new rules about confidentiality in an effort to prevent upcoming story lines from leaking to the media.

In a new Hollywood Reporter interview with castmates and series creator Dan Fogelman, Mandy Moore reveals security on set is like no other - because writers and producers are determined to keep plot points from getting out ahead of the start of the show's second season.

"It wasn't like this last year," says Moore, who plays Pearson family mom Rebecca on TV. "It's, like, suddenly we're on (TV drama) Lost."

And Fogelman admits many of the plot points change as the season progresses, because things happen in his actors' lives that prompt a rethink - like Chrissy Metz's real-life weightloss, which overshadows that of her character Kate Pearson.

"The plan we had for the character and what Chrissy's been doing have been working in tandem, with a talk once a year of, like, 'Hey, here's what we're thinking...,'" Fogelman explains to the publication, "so we have a general long-term plan that we've all talked about, and we will adjust the plan as needed. I mean, that's life, right?"