With the war with the Wasp empire behind them Collegium begins to take an interest in the wider world. Stenwold however believes it is inevitable that the war will begin again. In order to ensure that one of the masters sympathetic to his cause gains the speakers podium he agrees to throw his backing behind an expedition to the fabled city of Khanaphes, sending his niece Cheerwell as an ambassador. Che is crippled in ways no doctor can mend, having become inapt as a result of being connected to Achaeos when the moths enacted their ritual. As a result she can no longer understand the technology of her Kinden. She also finds herself haunted by Achaeos' ghost. Meanwhile Empress Seda has consolidated her power within the empire. Tharlric finds himself trapped, horrified by the empress' strange practices; he jumps at the chance to lead a wasp exhibition to Khanaphes. However someone very high up in the empire wants him dead.
Thalric and Totho have always been the most complex characters in the series and with both taking a centre stage in this book the character development is exceptionally good. Tharlric is a man divided against himself. His beliefs and very self-perceptions have been shattered and he struggles to find out who he really is. Totho still longs for Che's approval but struggles with self-loathing for his actions during the war. Che also grows considerably in this volume and it was interesting seeing her being truly caught between the worlds of apt and inapt.
The world building takes several steps forwards as well with some tantalizing hints given about the history of the world.
Tchaikovsky has a gift for writing large-scale battles and outdoes himself here again.
Overall very strong character-development and first-class world building combine to take this series to the next level. 9/10.