It shouldn’t work at all, that willpower and concentration and perception should shift mountains. Nothing else in the world works this way. People cannot stop avalanches by dancing well, or make storms happen by refining their hearing. And on some level, you’ve always known that this was there, making your will manifest. This … whatever it is. [loc. 1543]
The Obelisk Gate starts where The Fifth Season stopped: Jemisin doesn't provide a recap, so it is worth reminding oneself of what happened in that novel. This middle volume of the trilogy introduces Nassun, Essun's daughter, but the focus is still very much Essun and her various emotional commitments: to Nassun, to her former mentor Alabaster, to the people of the hidden sanctuary Castrima.
We learn a great deal more about the nature of orogeny, the ways in which it manifests in the young, and the consequences if it's not controlled. Jemisin also reveals the nature of Alabaster's great plan, and the motivations of those ranged against him. Vast, planet-shaking events are in train. Yet, though the plot advancement was gripping, I found I wasn't as emotionally engaged as by The Fifth Season, and I'm not quite sure why. Perhaps the wider focus, perhaps just 'middle book' syndrome. I did feel that some fairly major acts by various characters (for instance, someone being accidentally turned to stone) were inconsequential: that those affected, and those who witnessed the events, didn't react as much as I would have expected. On the other hand, this is not our world. Many of the characters have grown up being treated as non-human: others have rebelled against the established order, and have lived with the hard decisions, life and death, that that implies.
There are a few instances of inaccurate word choice: 'ostensibly administers the syringe’s contents' [loc. 911] for instance, when 'conspicuously' or 'deliberately' might have worked better. And I'm still not entirely sure about the second-person voice: it can draw the reader in, but also alienate when the character's views, reactions, individuality don't make sense to that reader. I did enjoy The Obelisk Gate, but I think I'll enjoy it more when I reread it immediately before the third volume of the trilogy.