Ok so, I don't know what's going on or if I'm just missing something, but it seems like there isn't a way for me to progress any further. 
I'm on the 13th floor of the Spirit Tower, need the 4th rail map. I've already gotten the 3 Tears of Light once and opened the treasure chests, but then ended up having to save my game and turn it off. When I was able to come back, I had to get the Tears of Light over again, of course, but the chests I had opened on the floor had saved and I still had the treasures. The problem is that the chest that has the key that I need also saved as being open...but I don't have the key anymore. :/ It's the locked door on the left side of the map that is blocking the switch. I've tried leaving the Spirit Tower and returning but the chest won't reappear...or maybe it isn't possible to reappear? If I can't reget that key then I can never get that rail map. I guess I don't know what to do at this point. D: Would anyone know a way around something like this?
I'm on the 13th floor of the Spirit Tower, need the 4th rail map. I've already gotten the 3 Tears of Light once and opened the treasure chests, but then ended up having to save my game and turn it off. When I was able to come back, I had to get the Tears of Light over again, of course, but the chests I had opened on the floor had saved and I still had the treasures. The problem is that the chest that has the key that I need also saved as being open...but I don't have the key anymore. :/ It's the locked door on the left side of the map that is blocking the switch. I've tried leaving the Spirit Tower and returning but the chest won't reappear...or maybe it isn't possible to reappear? If I can't reget that key then I can never get that rail map. I guess I don't know what to do at this point. D: Would anyone know a way around something like this?