Tripitaka is visited by the ghost of the previous king, murdered and usurped by the Red Hog Demon who now plans to sacrifice the king's daughter and heir to the new pig-god.
We've seen this plot done before in Monkey, with only the Pigsy-as-god sub-plot to keep things interesting. Pigsy himself spends most of the episode as a statue, and so isn't in it much, although there is a good moment when Monkey (inevitably) fights with the demon and the two of them cloud fly and duel around the giant Pigsy statue.
There is also the matter of the princess, who is one of the strongest female characters in the series (she doesn't fall in love with Tripitaka at all). Once Monkey has liberated her from prison - which she could have escaped from by herself only she had promised the demon she wouldn't - she quickly takes charge of the rebels against the Red Hog Demon.
The actresses playing the princess give an eccentric (yet distinctive and fitting) performance - I would say a mix of childlike naivety with intelligence (it is her that comes up with the plan to disarm the Red Hog Demon of his magic bamboo, not Monkey) and charisma - that, once again for this series, is perfectly matched by both the physical actress and voice-actress.
Not the strongest episode of Monkey, but worthwhile in its own way.