Red light leads to a three path room, also empty of encounters and with another red light.
It takes all three paths to find the one to the stairs down. There are two encounters. One is just trivial level zero slimes, and another with a band of giant hobgoblins. They're still low level, but you get a frightening moment when Alice takes the reflected damage from one of Sessha's knives straight to the face. Looks like this battle has random targets for physical attacks!
The way through is to get Willis to shoot them with elemental arrows, using your two layers of resistance and relatively low damage of the weapon to polish off one hobgoblin per successful hit while taking minimal damage.
The third room contains stairs and a rewards chest. Just a token amount of money, unfortunately. Still, it's a start.
Everyone's still at full, but Alice is now at 49/60 MP
The third floor you enter has a pair of large stone statues of a platypus-type creature, and although looking up all remains mist, the edges of the clearings are full of broken stones and bricks rather than it being a more seamless transition into jungle.
There are no red lights visible, and there is only one exit to these stairs, ahead of you. But Uncle has an idea.
Uncle has two options for you. He has a spell which he thinks can be used as virtual companions, for purposes of keeping rooms in place. He can do six of these before running out of mana. He's not certain it'll work, and they can't fight, like at all, but thinks it's worth a try.
Or he'll spend his mana trying experiments to figure out how to map this place.
Only way is forwards. But are you going to noodle around on the floor a bit? Hunt for a downstairs? And is Uncle going to try out his breadcrumb spell or work on figuring out how to map here?