AceShowbiz - Eddie Redmayne and Katherine Waterston were disappointed when they first checked the script of the new "Fantastic Beasts" sequel - because it didn't include a big romance for their characters.

The castmates were hoping their characters, Newt and Tina, would get together in the new film, but Redmayne now admits they have to work at being an item.

"It's desperate because they're sort of pining for each other, but things have gone awry," the British actor tells BuzzFeed. "Part of this film is about them re-finding each other...

"We were quite excited at the end of the last film. We thought, Oh my God, we're going to get to have a lot of fun working together on this film! And then the script arrived and it became clear that it wasn't going to be that easy. We're going to have to work for this romance."

"I'm hoping for an extraordinary (author and screenwriter) J.K. Rowling romance," he adds. "We know that we end up together, basically... Jo (Rowling) sort of tells us bits, but I don't know. I loved our bit in this film. It's so complicated. It's complicated."

His castmate adds, "It's complicated... It's a long-distance relationship...! There's a lot going on, so it's hard to just have a cup of tea and catch up and sort things out. But that's fun. It's fun to have it be complex and surprising and rich."

The co-stars also warn film fans the sequel is much darker than the last film: "I think Jo loves that. In fact, I think she even said that to me on set," Eddie recalls. "She was like, 'I just love it when it gets darker'."

Katherine adds, "It's more complex. I think it'll be a really fun journey to revisit and look for clues and things you might have missed the first time. It's really dense and full of interesting dynamics and relationships and wonderful wizarding lore."