Even as director Paul Feig signaled the start of production on "Ghostbusters," potential plot details have surfaced about Sony's female-led franchise reboot.

Citing "script spies," the Boston Herald reports Melissa McCarthy and Kristen Wiig will play unknown authors who publish a book asserting that ghosts are real. Their writing gains unwelcome attention a few years later, after Wiig lands a teaching position at Columbia University, and she's soon laughed out of academia. The two later team with supernatural sleuths played by Kate McKinnon and Leslie Jones, and save the day when ghosts invade Manhattan.

While this "Ghostbusters," like the 1984 original, is set in New York City, it's being filmed primarily in Boston.

The newspaper contends it can "reliably report" that Slimer will return for the reboot, but it's unknown whether original cast members Dan Aykroyd and Bill Murray will make cameos. “They are negotiating,” its spy said. “But, of course, no one can get a hold of Murray.”

Aykroyd, who created the franchise with the late Harold Ramis and serves as an executive producer of the reboot, recently told SPINOFF that his inclusion in the film is entirely up to Feig. "If asked, I will show up and be of service. If not, it’s totally fine with me," he said. "I leave powerful talent like that alone to do their thing."

Of course, if Aykroyd or Murray do make an appearance, they won't be playing their "Ghostbusters" characters Peter Venkman and Ray Stanz.

One actor who definitely won't be appearing is "The Amazing Spider-Man" series veteran Emma Stone, who turned down a role in the film. "The script was really funny,” she told "Wall Street Journal Magazine." “It just didn’t feel like the right time for me. A franchise is a big commitment — it’s a whole thing. I think maybe I need a minute before I dive back into that water.”

The film, which also stars Chris Hemsworth as the Ghostbusters' receptionist, arrives July 22, 2016.