In what doesn’t come as a major surprise, following the sad loss of Harold Ramis, Ghostbusters III is being rewritten, according to The Hollywood Reporter. It’s said that the rewrites are nothing massively substantial, with Ramis only set for a cameo appearance.
As for the overall arc of Ghostbusters III, it’s said that the movie will focus on a new generation of Ghostbusters, with cameos originally planned for the original Ghostbusters team. There’s also been constant he’s in/he’s out chatter about Bill Murray’s involvement.
In terms of specifics, Dan Aykroyd has previously described the plot of Ghostbusters III as, “It’s based on new research that’s being done in particle physics by the young men and women at Columbia University… Basically, there’s research being done that I can say that the world or the dimension that we live in, our four planes of existence, length, height, width and time, become threatened by some of the research that’s being done. Ghostbusters — new Ghostbusters — have to come and solve the problem.”
Expect more on this as it develops.