Monsters of Men brilliantly concludes the series begun with the Knife of Letting Go. However I must warn that for many readers the ending may seem unsatisfying. If you've seen Inception and you did not mind the open ending then you'll still enjoy the conclusion here.
Yet again the writing is concise, superb and sophisticated, opening up deep themes and ideas that encourage the reader to think both logically and emotionally as to how they would respond in Todd or Viola's place. How would you keep your sanity while the world was disintegrating into war around you and to protect the one person you truly loved required much compromise?
The author brilliantly produces psychological turmoil in his protagonist yet again but this time deepens it to new levels. I personally found it a very deep and yet dark ending to a YA series. In fact it is definitely one of the most unique YA series I have read for those reasons.
The entire power of this series is that it encourages thought about the moral consequences of our actions and the conflicts that emanate through love and war. In many ways Monsters of Men is a science fiction, in many ways it mirrors wars of the past, in others it's a love story and a tragedy. Whatever you as a reader look for within a novel you can find in this trilogy.