In the 'Red Rising' sci-fi trilogy a caste system has been imposed on humans, who now live on planets and moons across the solar system. People are divided into 'color' groups, each of which has a defined place in society. There are a wide array of classes including: Gold, the iron-fisted rulers; Gray, police and military; Blue, pilots and navigators; Yellow, scientists and doctors; Orange, mechanics; Brown, servants; Pink, sex workers; Obsidian, warriors; and the very lowly Red, menial laborers and miners. As the series begins 16-year-old Darrow of Lykos is a Red miner who lives in the bowels of Mars and has a job as a helldiver - the operator of a huge, dangerous, scorching hot drilling machine.
As the trilogy opens, the execution of Darrow's teenage wife by a Gold ruler leads to Darrow being genetically and physically altered to resemble a Gold. Darrow then infiltrates Gold society, trains at an elite military academy, becomes a combat leader, etc. - all with the secret goal of overthrowing Gold rule so Reds (and other colors) can have freedom and better lives.
In the second book Darrow, who has earned the sobriquet 'Reaper' for his ferocious battle skills and many kills, manages to start a civil war among the most prestigious (and greedy) Gold families. However Darrow's plans go awry at the end of the second book when his lowly status as a Red is exposed, to the absolute horror of all the Golds.
As 'Morning Star' - the third book in the trilogy - opens, Darrow has been tortured, bound, immobilized in a horrific dark cell, almost starved....and is about to be transferred to his worst enemy for dissection. Darrow is rescued and reunited with his most loyal friends, who call themselves 'The Sons of Ares'. The Sons hope to convince the mighty Obsidian warriors to join them so their united armies can start a revolution of the lower colors against the Golds - an almost impossible undertaking.
In the course of the story there's a great deal of strategizing, shooting, hacking off limbs, lopping off heads, torturing, stabbing, killing, facing old friends who've become opponents, facing old enemies who REALLY hate Darrow now, betrayals, backstabbing, clever manipulations ...everything you'd expect in a war/adventure story. Darrow even gets to use his helldiver knowledge and skills in some of the most impressive (to me) parts of the book.
Pierce Brown has done a masterful job of 'inventing' all manner of weapons, armor, aircraft, bombs, etc. for these books, which are fascinating to read about (though rather mysterious to me). The book's hero, Darrow, is a very clever leader, often able to out-think his enemies. Nevertheless, all the fighting is very hard on the young man, not just physically, but because he loves and values those Golds who were once his friends and allies - and who he now must destroy.
For a needed change of pace there are also some lighter scenes in the story, including family reunions, drinking and carousing, joking and jesting, and even some mild romance. By the end of the book there might even be a brighter future for humanity.
My one quibble with the book is that the battle scenes are so complicated it's sometimes hard to follow the action. Still, I'm sure many readers enjoy these parts.
Morning Star is a fine conclusion to the trilogy, which is very good. Highly recommended to sci-fi fans.