Though the American adaptation of the British mystery series “Broadchurch” may seem odd and unnecessary at first blush, to the cast of Fox’s “Gracepoint,” it’s the next logical step in telling the series’ powerful story. The actors arrived at the Los Angeles County Museum of Art Tuesday to preview the series, premiering at 9 p.m. Oct. 2.

“I thought this was such a great story, such great characters, it has to be seen by more people,” said Jacki Weaver, noting that while the British show is stunning in its own right, comparatively few American eyes have seen it. “The only way to do that is to convert it into the American vernacular and make it about people that everyday Americans will recognize.”

“Gracepoint,” like “Broadchurch,” follows the events of a town in crisis after the mysterious and heartbreaking murder of a young boy. The bones of the story will remain the same, though will be set in a small Northern California town as opposed to a British town.

“I thought, ‘That’s a novel idea,’” exclaimed David Tennant, who plays lead Detective Emmett Carter. Tennant also stars in the British series, now filming its second season, as the similar-but-different Detective Alec Hardy, and is the only “Broadchurch” vet in the new series.

“I thought doing the British show was such an extraordinary experience and when it broadcast, it created such a stir,” he said. “So, I thought ‘Well, I’m not going to miss out on the chance to tell this story to a whole new audience that hadn’t heard it yet.'”

“I didn’t set out to be self-consciously different,” Tennant added of his new on-screen persona. “The given circumstances are similar — he’s going to look quite similar because I’m doing it,” he laughed, “but I just tried to approach each scene as openly and without preconceptions, and therefore the character does develop in slightly different ways.” Tennant cited “Gracepoint’s” cast and writers as being helpful in his transitioning to a new role, and promised new and different twists and turns for the story. “It’s not just repeating the same,” he said, “and I thought I’d just ty to be open to how that seems to come to life.”

Many of Tennant’s castmates admitted to avoiding the British series, wanting to keep “Gracepoint” as original and distinct as possible, though for Anna Gunn, who plays Detective Ellie Miller, devouring the original series was a no-brainer. “I had no compunction about watching it,” Gunn said, sharing past experiences of working in a theatre company that would intentionally double-cast the same roles. “I think it’s a really great opportunity, and a great gift, for an actor to be able to pull back from the story and watch it from a broader or adjusted point of view.

“When you immerse yourself right into it sometimes you forget the perspective that a director would have, of the whole story and what your part is in that story,” she said.

Gunn also said that she took inspiration from Olivia Colman’s performance as Detective Miller to find the essence of the character. Virginia Kull agreed, noting that Colman and Jodie Whittaker, “Broadchurch’s” Beth, were instrumental in helping her prep for the dark and emotionally taxing role of the mother of a murdered child. “It lit a little fire under me and said, ‘You’ve got amazing people who have blazed the trail’ and it made me step up and work that much harder.”

Ultimately, the cast of “Gracepoint” stressed that despite its differences the series strives for the same heart and takeaway as its predecessor. “If they’re like me,” Weaver says of the “Gracepoint” audience, “they’ll come away having been moved, having been shocked and having been touched.”

“I think the thing is it’s about a family who loses a child, which is the most awful, dreadful, the worst human experience that can manifest and that’s a universal thing,” added Tennant. “That’s the same the world over.”