Alright guys, I beat this game about 5 years ago and decided to give it another run-through.

I have just met Sephiroth in the basement of the haunted mansion and he said he was "going north past mt. nibel" for the reunion.

I have entered and went through the cave numerous times and keep coming out at the town w/ the rocket. I talk to everyone there and it seems I cannot do anything there.
This is the only place I can seem to be able to exit to out of the nibel mountain/caves.

Any help?

-NXIII