Roberto Orci, co-writer of director J.J. Abram's highly anticipated Star Trek movie, told SCI FI Wire that the tightly guarded story for the upcoming franchise reboot depends heavily on the appearance of original series star Leonard Nimoy.

Orci (Transformers) added that the movie will explore Trek history that hasn't been mined before and confirmed that the story will take place before the events of the original series.

"There were many, many elements of the story that we had talked about just theoretically if ever Star Trek were to come back," Orci said in an interview in November. "There was lots of stuff we wanted to do, and that was a blessing. Normally you don't have that much investment and research for a project you get hired to do. If you are a fan of [classic] Star Trek, there is a lot of unexplored history. With the original series, there was so much that could have come before it. It felt like it has been The Next Generation and The Next, Next Generation for so long, it seemed like a fresh thing to go back to the source and to go back to what happened before it."

The crux of the screenplay involves the appearance of Nimoy in his iconic role as Spock. "I think a lot of people were speculating that we must have had multiple ideas [for the script]," Orci said. "The truth is that we took a gigantic gamble in terms of the movie we wanted to do, and it was essential that we had Nimoy. Frankly, I didn't understand any other way to do it. We didn't have a Plan B. I think that would have shown that we didn't have a true, singular vision of what we wanted to do, so it was essential for us to get Nimoy. It was a gigantic gamble, and I can't even believe that J.J. supported that kind of a gamble, but I think he understood it was the way to do it and a way to get the blessing for Star Trek, to show there is continuity for the spirit of what it was before. So when Nimoy said yes, not only as a fan was it a relief--if that didn't work, I don't know where we would be!"

Orci, who previously tackled a beloved franchise with Transformers (which he co-wrote with partner Alex Kurtzman), said that adapting Trek was even harder because of the dedicated fan base watching every move.

"The dangers are that now you are opening up yourself to the fact that the fans know what you know about the characters," Orci said. "They have their own ideas about what should be done and what is right for the franchise. So the goal with this movie is twofold. One is to make sure that the fans--who have been the stewards of the continuity and who are some of the most savvy and intelligent fans of any franchise ever--that they be satisfied with anything that has the name Star Trek on it. But, more importantly, the goal is really to introduce casual fans and people who don't know Star Trek at all to this universe and to connect it to today. ... The goal of Star Trek ... is that if you don't like sci-fi or know Star Trek, this will bring you into the world." Star Trek opens on Christmas Day 2008.