Note: Ancillary Mercy is the third book in the Imperial Radch series, following Ancillary Justice and Ancillary Sword. The trilogy is one long story and should be read from the beginning.
I spent a lot of my review for Ancillary Sword snarking about the unpronounceable names of characters and places. I did this because the plot itself was kind of a mess and not super engaging. Apparently, Ann Leckie took my feedback to heart, went back in time, and wrote Ancillary Mercy. It is the only way I can explain the leap in quality from the second installment to the third. Attaining the same heights of brilliance as Ancillary Justice, the finale pays off on its various themes and narrative strands to strong effect.
Ancillary Mercy begins just after the events that concluded Ancillary Sword. It also features an actual recap and re-introduction of key characters. This was sorely missed in Ancillary Sword, a novel that operated on the assumption the reader had memorized the previous volume. As work proceeds to repair the Undergarden an unknown ancillary called Sphene is discovered that has been hiding in the bowels of Athoek Station. Then a Presger emissary shows up for reasons she keeps inscrutable and sets everyone else on edge. Soon after word reaches Breq that Tstur Palace has fallen to the tyrant version of Anaander Miannai and all indications are she is on her way to capture Athoek Station and seeking revenge on Breq. Forces collide, plans go awry, and that mysterious Presger gun’s real purpose is revealed.
Ancillary Mercy largely jettisons the plot development from Ancillary Sword. The main characters in that book including Raughd, Fosyth Denche, Captain Hetnys, and Basnaaid barely feature. The final installment brings the focus back to Breq and the crew of the Mercy of Kalr for the better. For her part, Breq spent all of Ancillary Sword pretending to be human. She outs herself at the end of that book and by the time Ancillary Mercy begins everyone knows that she is the Justice of Toren in ancillary form.
This forces Breq to come to terms with her identity and the central question of the series: What is a person? Breq is a ship AI with no ship, a part of a whole that has been reduced to only a part. She comes to realize she relies on Mercy of Kalr to send her ongoing information on the crew. Not just to know what is going on, but to help fill the hole left by the absence of her own doomed crew a decade before. She is driven by revenge but also sees that revenge is not an endgame and there has to be something more.
Ancillary Mercy explores more what it means to be an ancillary for an AI, and what it means to be an AI without ancillaries. Mercy of Kalr, Athoek Station, Sphene, Sword of Atagaris, Breq/Justice of Toren, and other ship AIs are all characters in this final installment, separate from their crew and captains. The Tyrant dismisses them as tools and does not believe they are in their own control, adamant that someone is controlling them but he is mistaken to devastating consequences.
Lieutenants Tisarwat, Ekalu, and Seivarden all have their own arcs to complete. After being largely sidelined in Ancillary Sword, Seivarden plays a larger role here and his own failings and man-out-of-time issues receive more attention. He is still a difficult character to root for, but you can at least admire him when he screws up no one is harder on themself than he is.
Ekalu grows into her own person outside of the shadow of Seivarden and Tisarwat proving herself the most capable of Mercy of Kalr’s lieutenants. Tisarwat is still struggling with who she is and fighting against the Anaander Miannai imprint on her mind from her time as an ancillary. She too does not know exactly who or what she is and ends up being one of the more tragic characters in the series.
The Ancillary series is not space opera, most of the big confrontations are verbal other than a couple of tense shootouts here and there. The series wraps up in an open-ended way that closes the current action but with the knowledge, the fight is not over, because the characters are still alive. Some questions are left unanswered. Most crucially is the notion that there may be more than two factions of Anaander Miannai out there. In the finale, I kept waiting for one of the main characters to be revealed as an ancillary for the third faction. This does not happen, although all signs point to someone filling that role and I have my suspicions who that most logically would be.
Ancillary Mercy ends with our surviving heroes getting a well-deserved rest but knowing more trials will come. Nothing ever ends and an end is only another beginning for the survivors.