The story continues to follow the exploits of protagonist Rik, his former unit The Foragers and his slightly suspicious patroness Asea.
It continues where the second book left off, regarding the disposition of a possible ally nation and its recently rescued queen-to-be. Rik finds out more about his father, and the very creepy Quan race of sentient soul-stealing squid are introduced.
Sardec, the commander of Rik's former unit, continues to develop nicely and I really like the air of ambiguity about Asea. I hope there are lots more Chronicles to come and it's very easy to see her being revealed as either an angel or a demon in later books.
Rik's nation (Talorea) and their enemy (Sardea) are vying for political advantage in a lesser border nation as well as the independent city of Harven. There's a mixture of political shenanigans, bloodshed and Lovecraftian arcane horror, and I think it works really well.
The pace is also nice and fast. I think I slightly criticised the previous book for sagging a bit in the middle, but The Queen's Assassin was thoroughly enjoyable from start to finish.