At last we reach the Underworld. ***Major Spoilers Ahead*** because the episode sort of peeved me. I feel as grouchy as a three-headed guard dog, although the episode definitely had its pluses as well.
Two big things that leap out at me are the flying shoes and the pearls.
First the shoes. Perhaps I’ve overlooked something, but as far as I remember (or can tell by glancing back through critical moments of the episodes) Luke gave Percy the shoes and then that was it for them. When Percy learns about the dangers of him taking to the air (the perfect moment to hand them over to Grover to use – and the moment when he did so in the book), nothing arises (so to speak) about the flying shoes. He never, as far as I can tell, gives them to Grover in the Disney+ series. Grover – before this episode – has never used them, even in places where he did in the book (which worked well as establishing them with Grover and underscoring Luke’s betrayal). But now that they are needed for the major plot point of that betrayal, Grover uses them early in the episode as the only groundwork for the later crucial scene. I assume something in an earlier episode that would have set this up hit the cutting room floor, but still it feels sloppy to me.
Speaking of Grover and sloppy (or should I say slobbery), Percy distributes the pearls right away in the episode and Grover loses his when briefly eaten by Cerberus (or at least caught in his mouth before emerging covered in slobber). Not Grover’s fault, as Percy assures him when he hands over another pearl to Grover, but still I hated they made Grover the heavy for Percy’s later mom-dilemma. Given how they’ve set up the uncaringness of the gods, this felt at first unnecessary. But then Poseidon showed up in the episode (more on that below). Nevertheless, thus the problem of the fourth pearl was solved.
So if the stomach acids of Cerberus dissolve the pearl, will he find himself suddenly in the ocean?
I loved the grove of Asphodel and the soul-trees of regret (very Vergilian Field of Mourning with its myrtle grove), but was sorry to have Annabeth pulled out of the Underground before the big action at Tartarus got going. Actually, I hated it. Having her there for the pit and a witness for what is really going on felt important. Plus she is a fun and central character. And nothing arose that would benefit from her absence. Why?? I’m sort of miffed.
And having Percy find the master bolt not in the palace of Hades also cut out some great moments from the books when Hades knows it’s there and Percy doesn’t. But in this episode Hades doesn’t want the bolt (at least not until he hears about Kronos and feels the need for a defense).
On the other hand, I love Hades the character in this episode. Very different than in the books, but as with Ares, a real upgrade in personality. And I’ve never liked the whole Hades must be unhappy with his lot bit (and thinking in the book that he wants a war to increase his kingdom never made any sense – 100% of the mortal population will end up down there with or without war). I like a Hades who likes his kingdom. The H gods (Hermes, Hephaestus, and Hades) are really the best of the lot in this series in terms of humaneness.
Poseidon also gets a H for human-feeling. The whole flashbacks to Sally taking Percy to a boarding school (fabulous job by Azriel Dalman as young Percy) set up a drawing in of Poseidon as a good guy (good god). How Sally knows so much about the gods’ family is still a question.
Ramblings 
