This is the third installment of the Cassandra Kresnov saga (are there more?). I quite enjoyed it. Better possibly that the previous two, the author seems to be getting the hang of the genre. There is plenty of action, Sandra meets her ‘sister’ and nemesis, spends time with her friends, time in hiding, and sorts out a blockade of Callay by rouge agents of the Federation. The whole ‘kill-switch’ idea of the novels title is a bit lame really and fills up chapters that could have been spent with the cool-integrated-killer-artificial-lifeform angle that one reads this book for. The Cassandra character does develop a little from the previous book, but the more interesting development is of Rhian Chu – the GI introduced in person at the end of book two (and referred to a lot previously). Killswitch is not going to change your world, it is really just another formulaic pulp-sci-fi yarn of no particular originality, but it is still worth a read if you like that sort of thing (clearly I do!).