How do you switch between Alm and Celica's story in Fire Emblem Gaiden?

I've been playing the original Fire Emblem Gaiden on an emulator for a while, and after clearing Zofia Castle, i talked to an NPC and was taken to Celica's story. I've finished the first few levels, but I'm wondering if it's possible to switch between Alm's and Celica's stories at will, as in an option in the menu, or do i always need to talk to an NPC?


Unfortunately, you'll need to play through quite a bit of story before you have that option without the NPC...it happens once they meet and decide to take different paths.