Most of the episode concerns various attempts by Monkey to gain possession of the Queen's magic fan, which can be used to quell the volcanoes so they can pass by. But although Monkey gets his hands on the fan by disguising himself as King Water Buffalo, the real King steals it back by disguising himself as Sandy.
The Queen captures Tripitaka in an attempt to get her fan back from Monkey. Tripitaka finds out that the Queen is bitter because her husband has run off with a human woman, but he tells her that to get her husband back she must ask the King to forgive her for her jealousy.
While this isn't as outrageously sexist as the likes of Star Trek's Turnabout Intruder, the idea that it is the woman's fault for the man's infidelity does make me cringe. Suffice to say that this does work and everyone makes it up at the end.
There are two noteworthy (in a good way) aspects to this episode. First is the way that every time King Water Buffalo gets into a fight - and it happens twice, first in a fight with Sandy and later a fight with Monkey - he has a group of minions that run in and join in the fight, then vanish without a comment when the fight is over. Pure set-piece fight scenes, with no attempt to disguise this.
The second is a scene that has to be seen to be believed, and I can only assume was included because the episode was under-running. After they have used the magic fan to make it rain and put out the volcanoes, Monkey, Pigsy and Sandy perform a curious and exceptionally silly dance to the Monkey theme song.
I only wish I could get some screenshots of the faces they pull; they're bizarre. Alas my PC isn't working properly at the moment for me to do this - I may come back to it if I get the chance.