I read this as the first part of a double book - combined with 'A Betrayal in Winter' these are the first two volumes of 'The Long Price' quartet as 'Shadow and Betrayal'. The remaining two volumes, 'An Autumn War' and 'The Price of Spring', are combined into a second double book, 'Seasons of War'.
The central conceit of the book (and the only magic so far) is that after long training, poets are able to write a poem of such power that it can embody (literally) an idea. The idea then takes anthropomorphic form (called an andat), but bound to the will of the poet. The cities of the Khaiem then use these 'andat' beings to enhance trade and to deter invasions and avoid war.
In the first book, one of the powerful trading nations attempts to pervert this power in a way that would kill the poet and thereby release his andat, thus leaving the region undefended against invasion. The method used is quite complicated, and ultimately fails, and it seems to me that it would be far, far simpler just to kill the poet directly. He seems to move freely around the city, regularly getting drunk, so it would hardly be difficult, and far less risky than a public ceremony where there are bound to be recriminations. Since there seem to be very few poets with an andat (only one per city), it would surely not be too difficult to arrange a mass killing of poets, and release all the andat beings at once. And why, when the power of the Khaiem rests almost entirely on these few poets, are they free to do as they please, unrestrained and unprotected (quite apart from the unwisdom of letting the andat loose to brew his plots).
Logic flaws aside, the book is well written and absorbing. It is set in an eastern-esque world with a Japanese or perhaps ancient Chinese feel, with robes and teahouses and an intriguing use of 'poses' with the hands to add layers of meaning to spoken communication. The city of Saraykehm is nicely drawn, civilised and more or less orderly, a hub of trade and politics, and perfectly believable. I liked the idea of kilns and food carts on every street corner, the public bathhouses where much of the private discussions go on, and the beggars who sing for their charity, a nice echo of the elegant slave songs which are the backdrop for the Khai's courts.
The andat is actually the most interesting character, with his perfect form and his deeply flawed personality and his determination to defeat his creator and return to a state of 'unbeing', all a creation of the poet Heshai's own mind. The other characters behave with strange logic. Liat, who appears to be capable of loving two men at once without understanding the consequences (she thinks they will all be friends!), is quite unbelievable. Amat, who has such a horrible time held captive (essentially) in the brothel, yet chooses to buy it later purely to fund herself, is not particularly believable either.
By the end, I was finding it increasingly hard to suspend disbelief long enough to follow the story. Nevertheless, I enjoyed the book, and I hope that the second volume is a little more soundly based.