I've been tromping around on level 6 ("Trapped") for a while, looking for a way to get back to level 5.
I have more or less completed the level, since I can access the stairs down at the end of the Sequentis area, but I can't find a way back up.
I did find
a secret staircase in the Halls of Fire (in the long hallway with the fireball-shooting head) that led back up to level 5. However this leads me into a room containing two fire elementals that blocks me off from the rest of level 5.
In short, I can't seem to figure out how to get back to the main area of level 5 and above. I'm trying to kill some green slimes I passed up earlier.
Is it too late to go back, or is there something I'm missing?