Nearly every story by this author is excellent. This one and Tangent set in the same universe may be the best ones I have read. I don't know of any useful way to tell you what happens in the story or its predecessor, but I strongly recommend you read them.
This is going to be a short review. The scores are all tens. I don't give a lot of tens, but this one deserves it. The only thing wrong with it is that it ends without the villains getting their just deserts. Of course that give hope that there will be sequel(s) to complete the story. I certainly look forward to reading more about these characters.
Another romp through the Looking Glass. They definately aren't in Kansas anymore.
Without giving up any plot or secrets I can say this: usually the second, sophomore, sequel is nothing compared to the original that inspired it. Not true here. This is good consistant writing with the plot as convoluted as ever but you can still follow it to a logical conclusion.
The bad guys are still out there and the good guys are still wearing white hats.
The only thing that makes this a science fiction is the "universe" in which it is set and the occassional linking with "other entities".
Again, I have to say this is as good as they get on line. Download this and print it for the young ladies in your family to show that it IS possible to be a girl, have an imagination, be a strong person without being an outcast because you know what you want and you aren't afraid to work hard for your goals.
Read it it's worth your time.