This is the final book of the Mistborn trilogy (although not the final book in the series, apparently? FictFact lists several more) and it is, I think, the best of the three.
In the first book we’re introduced to a world where the God lives among them and is cruel. The common people are oppressed and the nobility have among them people with the power to ingest and use metals to activate special abilities (enhanced sight or strength, for example). We meet a group of people hoping to overthrow the Lord Ruler and create a better world.
The overthrow works, although not as planned, and a new government arises. The second book deals with the attempt to set up and modify the new government to make it equitable. It’s harder than you think to change the world.
In this book, we see the world in a state of collapse. The ash from the volcanoes is coming harder and faster, burying the plants and bringing the real risk of starvation everywhere. The mists, which had previously been harmless, now kill some of the people who are exposed to them. The mists are coming earlier in the day and dissipating later, making the window of time where anyone can farm or travel shorter.
The emperor and his wife are trying to bring the rebel cities under the banner of the empire so they can consolidate the population in a more defensible position, while also trying to defeat the koloss armies that are roaming the world. These kolass are not unlike trolls, large and violent and terrifying.
They’re also seeking out the location of hidden storage caverns the Lord Ruler put into place before his death, which contain supplies that can sustain the empire and perhaps a key to destroying the evil force that is trying to end the world.
The end was not as I expected. I really appreciated that he tied together all the strands of plot and background, strands I hadn’t even realized WERE strands, thinking them to just be characters. This was beautifully done. Definitely read the previous two books first, don’t just jump in here.