From recall, go s,e,se,ne,e,s,se,s,sw,s,se,s,sw,w,n,d,n,w,w,nw,n,n,e,ne. Hidden door to the east. Search it but it is locked. Key is from the wizards nw and w. Once you get the key and unlock the door, you may want to hide it on the ground as it is vanish-death. The area below is all no-recall meaning you can get stuck locked behind the door if you're not careful.
Follow the fairly linear path around heading generally east. You'll eventually encounter a dizzy room. SW past that is the 3x3 throne area. Queen is in the middle (CPK).
Non-aggro and she is dispellable via cast. Casts extinction, confusion, web, bolts, corrode weapon, and the other standard assortment of spells. She also dispels debuffs off herself occasionally. If things are going bad, its relatively safe to calm as she does not re-aggro. Just watch out for calming mid her cast.
Special mechanics
Pulls a lever mid-fight teleporting you to the dungeon area. A master of agony will aggro on you. Its a matter of running back the short distance to Viridis and engaging again.
Occasionally an elite guard can just appear in the room and join the fight. They are spookable via mask.