Multi-Party mode

So, when you enter a town/dungeon/etc, the game saves your location on the parent map. It's how Warp knows where to bring you. When I was recently changing around the characters to wait around in Figaro instead of Narshe, I forgot to change a map load, and ended up exiting Figaro near Kohlinghen and ending up outside of Narshe, with no way to get back, since Figaro castle was no longer there. I'd anticipate that the same thing would happen if you did multi-party-select outside of a single town/dungeon.

Example:
1. Both parties are on the world map.
2. Party 1 enters South Figaro, setting the parent map to just outside South Figaro.
3. Switch to Party 2, which enters Mobliz, setting the parent map to just outside of Mobliz.
4. Switch to Party 1, who exits South Figaro. They get transported across the world and end up outside Mobliz.

I haven't tested this theory, but I believe it's what would happen.