So many unanswered questions....
1. Who exactly was Zero and why is he so determinded to get rid of all these spooks? And how does he know all these spooks are back on earth?
2. Are Spencer and Kong married? Do they have children?
3. How did Zero come to form the Ghost Busters agency and how did her go about hiring Spence and Kong?
4. How did Spence and Kong learn to Ghost Bust? Was it on the job training? Did they have to go to school?
5. How did Tracey end up joining the group?
And so on and so on. Anybody care to add to the list of unanswered questions?