There has never been a science fiction debut novel that has been as well received as Ancillary Justice. Ann Leckie's novel is the first book to win the Hugo, Nebula and Clark awards and has sold handsomely. Like a lot of sci-fi debuts, Ancillary Justice is part one of a trilogy, but how does a writer follow up such a successful first novel and make sure the sequel does not disappoint readers’ high expectations? An obvious answer would be to give the reader more of the same, so Ancillary Sword continues where Ancillary Justice left off in terms of both story and debate. Breq (a human ancillary who is all that remains of the controlling AI of the vast starship, Justice of Toren) has been given command of a warship and sent to protect the Athoeksystem.

The story of Ancillary Sword follows the same main characters (Breq, Lieutenant Silvadene, et al) and the same storyline - the growing civil war between the two halvesof Anaander Mianaai, humanity’s tyrannical leader in Leckie's vision of the future. The same debates about colonialism, identity, race and class are explored again, but not in a way that retreads the same ground. Ancillary Sword makes sure it pleases the established fan base, as the reader will find the same characters and plots they enjoyed in Ancillary Justice.

Rehashing an earlier novel is a surefire route to failure. Aside from the obvious criticism of lack of imagination, it would be nearly impossible to repeat the success of Ancillary Justice. So it is necessary for the sequel to be different to some degree.

Ancillary Sword introduces some new characters, mainly to replenish the cast after the bloody climax of book one, and these complement the existing cast well. Breq is able to find self-important, petty tyrants wherever she goes and the new antagonists are just as entertaining as the old ones.

The most noticeable difference with the sequel is in the narrative. Firstly,the structure of Ancillary Sword is quite different to Ancillary Justice, as the former has a significant proportion of the story told through flashbacks, which the latter does not. Around a third of Ancillary Justice was the story of Justice of Toren, filling in the events which led to her becoming Breq and discovering the division in Anaander Mianaai. This is told in tandem to Breq’s story in the present, they both have different perspectives as one is from the point of view of a starship and the other a lone ancillary. By contrast Ancillary Sword follows a simple linear narrative with only Breq's present point of view.

The substance of the plot is also different. Ancillary Justice followed the trajectory of a revenge story, whereas Ancillary Sword is a conspiracy thriller. In part one of the trilogy, we find out why Justice of Toren was destroyed and see Breq's attempts to avenge herself. In part two,Breq is sent to a new system and must find out which officers are loyal to which half of AnaanderMianaai. The very different plots make for very different tones and emotional journeys for the characters, reading the sequel is a very different experience to reading part one.

The location is another key difference between the two novels. Ancillary Sword is set in only one location, whereas Ancillary Justice had three main locations and several minor ones. The sequel is much more claustrophobic, as well as exploring this location in much more detail. Another aspect of this difference is that Breq's relationships to the new characters are more developed than those in book one. All these factors make Ancillary Sword a very different read to Ancillary Justice.

In some ways Ancillary Sword is very similar to Ancillary Justice and in othersit is very different. The characters, arcplot and broad outlines of the novel are very similar but the specifics are very different. Personally, I preferred the plot of Ancillary Justice, as the revenge story gave the novel more momentum. Also, the characters of the first book were more interesting.

The better developed location of the sequel, along with the familiar arc plot and characters of the first part, did make Ancillary Sword an entertaining read. However the plot and structure changes meant the novel was less engrossing than Ancillary Justice.

In terms of the wider debate about how to follow up an engaging original with an enjoyable sequel, I would ultimately erron the side of preserving as many aspects of the successful original. This said, the specifics of the series needs to be taken into account, the mistakes of Ancillary Sword could be the successes of a different novel. I enjoyed reading both books a lot but in trying to be different, Ancillary Sword loses some of what made Ancillary Justice so great.