Next month, 20th Century Fox’s “Prometheus” will finally touch down in theaters, but for screenwriter Jon Spaihts, the journey began nearly three years ago.Spaihts, who shares a writing credit on “Prometheus” with “Lost” creator Damon Lindelof, said the idea for the Alien project was hatched from a general meeting he took at Scott Free, director Ridley Scott’s production company. “After going over a few other projects, Michael Costigan, president of the company, mentioned they wanted to revisit the ‘Alien’ universe,” the writer recalls. Acknowledging that the “Alien” franchise with Sigourney Weaver couldn’t extend any further into the future, Costigan and Spaihts agreed that the only way to revisit the “Alien” franchise was to go back. “I just started riffing about how you’d have to do it and what the secrets behind the first film would have to be,” he says. “At the end of it, he asked if I could write down what I said and email it to Ridley, who was editing ‘Robin Hood’ at the time.” Months later, Fox brought in Lindelof to do a re-write with Spaihts, who praised the Emmy-winning writer for being “extremely respectful” of the original script. “We worked sequentially, not at the same time so I can’t say that we collaborated,” Spaihts says of Lindelof’s involvement. “(But) he came up with some cool new ideas and ways of deepening and complicating certain relationships and ideas and I think it really works.” Opening in the U.S. on June 8, “Prometheus” follows a team of explorers who discover a clue to the origins of mankind on Earth, leading them on a journey through the darkest corners of the universe. Noomi Rapace, Charlize Theron and Michael Fassbender star. Fox had long-insisted that “Prometheus” carried only ‘strands of D.N.A.’ from Scott’s original “Alien” film, with studio execs publicly denying that the film was an “Alien” prequel. But Scott himself obliquely admitted in March at WonderCon that the storylines had become more intertwined during development, affirming what movie bloggers had been conjecturing for months. “There’s a larger philosophical debate around that debate,” Spaihts says of the “Alien” disclaimer, adding that he wasn’t involved in the decision to play coy — nor did he understand it. “Certainly it’s set in the universe of ‘Alien’ and prior to the events of ‘Alien,’” he says. Still, the studio’s plans for “Prometheus” are epic in scale. The reported $150 million tentpole, hinging on box office, could get the franchise treatment, with Spaihts revealing that the “Prometheus” storyline calls for more pics. “The story I develeoped with Ridley unfolded in the context of a larger arc that we imagine playing out,” the writer says. “That’s been discussed from the very beginning.” One Fox exec points to Scott’s involvement as the key factor. “It all depends on Ridley,” the exec says. “We’ll obviously be prepared if and when the time comes.” For now, the final cut of “Prometheus” has been delivered to Fox, who will begin press screenings for the R-rated film in the coming weeks. As for his next endeavor, Spaihts is currently writing another familiar property, Universal’s reboot of “The Mummy,” which the screenwriter promises will be genuinely dark and scary. “I think it’s possible find a great story in whatever framework you’ve been asked to write in,” he says of Hollywood’s current reboot rage. “Whether you’re continuing a saga or reinventing one, there should always be potential to make good art.” Spaihts is repped by Paradigm and Circle of Confusion.