My cousin reached the same spot as you last night. This is what happened:
He went up the stairs from the throne room and Zrell, Rajida, Neophytes, and an Ogre were standing in the room the left. There was an open door going forward with 1 guard and a scrying eye, and an open door going to the right with 2 guards. The door going forward had a red border, and was restricted.
When he went left, he got a cutscene with Z'Rell telling Radija along the lines of: "Do not let anyone up on the upper floors"
Radija then answers "Does that include you, Z'Rell?"
Z'rell then reads my cousin's character's mind and wants to know what he did with the goblins. Instead of deceiving/persuading her, he just attacks her and this aggroed every guard on first and second floors. He dies to them, then goes back to a save BEFORE entering the second floor and the Z'Rell cutscene.
This time, he sneaked through the door on the right, the Z'Rell cutscene did not play and none of the guards were aggroed. A guard then stops him. He succeeds the persuasion check, and the guard tells him he's off the hook this time but if he gets caught again he won't be so lucky. He then gets caught a second time and this time he had the option to 1. go to jail; 2. pay a bribe; 3. pay another amount 4. attack. So he rolls back to before entering the second floor.
This time he walked forward through the red-bordered door, the Z'Rell cutscene did not play, none of the guards were aggroed. However he did get a short scene with a guard going: You have entered a restricted area, you better have a good reason for being here."
You mentioned the Z'Rell cutscene played for you, and then you saved after speaking to Radija. Z'Rell tells Radija not to let anyone on the upper floors, so because you saved after speaking to Radija, I believe you did save the aggro on to the file just by being on the second floor. If you enter the upper floors/enter areas with red doors, I believe it automatically counts as trespassing. If you hover over the doorframes, it'll show you red or white. If it's white, it means it's safe to enter.
I told my cousin to let them take him to jail, so the guards arrest him and ONLY his main character was taken. The other three were still free.
Once in jail, I had him jump through the green hole in the ground, and that took him to the Oubliette (blood lake miasma underneath Moonrise). Please note that if you are taken to jail, the guards will take all your weapons and items in your inventory, and you need to retrieve it from the evidence box xD.
Check and see if you can use a waypoint to have your characters regroup. If you can, great. If you can't, grab some weapons from your other character's inventories and equip them on the character that got jailed. Making your way out of the oubliette, you'll need to fight 2 hook horrors.
^If you still have the option to go to jail, I think this may be the easiest way for you to keep your save file without too difficult of a fight.
