This is not a direct sequel to The Silent Tower and Silcon Mage- the two previous books were a story in themselves, and this one takes place some time later. It was nice to see Antryg and Joanna again although this book shares too many of the same scenes as the last two. I felt the plot spent too long not going anywhere, with Antryg skipping about the Citadel evading enemies; and there was an awful lot of babble about how the energies actually work. But it shows Antryg's intelligence and resourcefulness, and lets Joanna have her own heroic moments as well. I did like it but it's best not to think too much about some of the plot complications.