They arrive at some sort of cave, with a floor covered with arcane inscriptions. It becomes very clear very quickly that this is not their intended destination, but a "ding" echoes through the caves and the portal closes behind them.
They're trapped. The magic feels odd and twisted in those tunnels, and periodically strong pulse passes through the walls, indifferently like a heartbeat.
The adventurers begin to navigate through the tunnels, and soon discover its inhabitants: twisted deformed forms that look like they're made out of chunks of flesh. They take many forms from walking moving piles.... to giant worms, forms resembling that of fiends, and even dagger.
And all of the whisper, giggle, cackle, scream and speak in dissonant chorus all the time. The voices of seemingly mindless creatures repeat things said by someone, somewhere, promise , and yell of despair. The adventurers battle.
Soon they encounter more creatures that resemble the adventurers themselves, those sometimes follow them and sometimes attack outright.
The long trek through the network of tunnels takes time and is not without wounded people. But eventually they reach a room with few dragon-shaped dwellers in it, and after defeating those, they find what seems to be a portal.
The circle lights up as they approach. And eventually they decide to step through as there's no other option they see.
----
They arrive somewhere that looks like somebody's dwelling. There are more circles on the floor, some blood splatters, and red liquid runs down some of the walls, disappearing upon touching the floor. Despite being indoor, it is raining.
The circles light up and zap one of the summons the adventurers brought in, banishing it. The adventurer's proceed through.
In a hall straight ahead of them the encounter a locked door with few impressions on it. The door is locked.
The adventurers proceed through the area. Passing through halls with many odd effects in them. One of them has falling leaves descending from ceiling. IN one of the room, there's a great circle ofglowing light in the air, and waterfall pouring from the ceiling. Another room is chilly and looks like a bedroom, full of pillows. In that room anther creature drops from the ceiling, makes few remarks and disappears by melting into floor.
There are other rooms guarded by big worms that giggle, cackle and spout nonsense, but the inhabitants are not hostile.
Another room had an odd floating object that looks like crystal heart, and few more inhabitants that become more anxious when adventurers approach it. The room linked to it is filled with clouds....
During their exploration they find few objects that look like some sort of keys fit for the door they encountered. They gather those odd runed stones and return to the door, and attempt to unlock it only to have the door snatch the keys from their hand and eat them.
But the door opens nevertheless.
Inside they find what looks like a library in a state of disarray and a door locks behind them. There's a pedestial with a book chaind to it, and this scene is familiar for one of the adventurers. A big book is attached to the pedestial with a chain and it looks alluring and inviting to read it. Out loud.
Seeing the doors are locked, they approach it, and start reading passages, ready to run off from it. Some passages are nonsensical, and some contain meaning. The pedestial below book lights up on occasion, releasing magical energy that passes through the book. But eventually the light fades and the pedestial stops reacting.
After several pages, the book flies up rips off the chain and attempts to defeat the adventurers but... is defeated after some struggle.
At which point a door opens with a click, and a strange looking woman, accompanies but odd looking rat enters the room, holding a tea cup in her left hand. She observes results of the fight and frowns.
She speaks, but speaks gibberish. However, the wards of the strange dwelling seem to obey her command, which is learned quickly by one of the adventurers who, upon kicking nearby book, gets wounded and has wards stripped from him.
Eventually, a communication becomes possible through a method that is painful for one of the adventurers.
While the "interpreter" adventurer is slowly bleeding, the woman demands answer - who the adventurers are and where they came from. And whether they intneded to harm her or her odd companion.
Eventually, just before the "interpreter" bleeds out, some conclusion is reached. The woman produces a scroll and hands it over to the advetnurers.
Then magic circle lights up on the floor, and the adventurers are sent back to their plane, into a seemingly random location, which just happens to be in a cave, knee deep in the water....
