Regina Shen: Endurance (book 4) begins with Regina Shen still on the run from the federation and dealing with the betrayal of her mother. Regina has all the keys to saving or destroying the federation and if she were anyone, but an outcast then she would be queen. However outcasts cannot even become citizens. This leaves Regina on the run and trying to figure out what she should do as allies become traitors and the federation follows her.
I found that Regina Shen: Endurance (book 4) was the best book in the series by far. This is the book where Regina truly decides her fate and the fate of the Federation. However I cannot seem to get over the simple fact that if the Federation had not made her an outcast most of the trouble could have been avoided. Regina really came into herself in this book as she was given more and more choices on what she could do with what she knew.