I've known the character involved for all of those 20 years and his/her ending was very sad.
In a way the series suffers a little for that reason because by this point she's kind of filling in on stuff that was hinted at in previous books (who Fury really is, the Mental Man concept, the Metaphysic Rebellion) and after all the in-book hype its hard to say that it could be brought to life on the page as well as it could be in our minds. The focus here is supposed to be the Rebellion's growing plans as it seeks to combat the upcoming Unity but what I find interesting is how May almost goes out of her way to avoid having good guys and bad guys in the argument, even though the Unity crew seems to come across as more rational in their acceptance of it (throughout the whole book May can't really seem to convince that the Rebellion's whole foundation is based on "my gut says this isn't a good idea" despite there being very little evidence its not a good idea) she puts plenty of sympathetic characters on the Rebellion side, including good ol' Uncle Rogi, he of the endless bystander status, making it difficult to immediately dismiss them as cranky people who just didn't get a good night's sleep. It adds a needed heft to the final appearances of a lot of the long time characters (balancing out that we never have to worry about Rogi because its clear that he lives since he's telling us the story) and a sense of tragedy as a bunch of people who hoped they were doing the right thing discovered the right thing had a cost or that it was never the right thing in the first place. All the close characters are believable as family, for better or for worse, whether its Marc's glowering superiority, Rogi's cowardly non-alcoholism, Jack's knowing innocence (in fact, watching him develop has been one of the real delights of this series), Diamond Mask's gradual comfort with herself or any of the random Remillards that pepper the landscape. But its the people who stick in the mind, the little interactions between Jack and Marc, Rogi and Dorothea, Dorothea and Jack, Rogi and Denis, any of the Remillards with each other, even the minor characters who populate the story toward the end, they have a close held bond to each other that only comes when they've really been alive, full of love and quarrels and disagreements and loss and joy. In a sense it seems like that May at times is suggesting in her backgrounding of important events, her structure of the series as an infinite closed loop fated to feed on itself, that history isn't perhaps the most important part of events, its merely the sequence that everyone agrees on.
Jack the bodiless and Dorothea MacDonald are fighting Jack's brother Marc who takes up the reins of the Rebel faction and supposedly wants Earth to retain its individuality and not join the Milieu in Unity but beneath all the Rebel dogma he is fomenting a secret plan of his own to advance the human race into a society of fully operant and metapyschic beings.
This one shows signs of being perhaps a little rushed, but given the overall quality of the series I think I can give Julian May some leeway here. Julian May wrote a couple of well-received science fiction stories in the early 50s, and then put fiction writing aside for several decades as she didn't think she could make a living doing it.
However, in effect, this trilogy - and the book which came before it - are merely explanations and fill in details which help the original Saga make sense. This is probably the best of the Trilogy, despite its abrupt ending - but it is still not as powerful or vibrant as the either the original four books of the Saga, nor the excellent Intervention.
At their head is a man obsessed with human superiority: Marc Remillard, scion of the family that almost singlehandedly led humanity into the Galactic Milieu, and one of the most formidable metapsychics ever. And only his brother, Jack the Bodiless, and the young woman called Diamond Mask - and the awesome power of their combined minds - can hope to lead the metaconcert to destroy Marc, Unify humanity, and pave the way for the Golden Age of the Galactic Milieu to begin . Annotation The eagerly awaited finale of a modern SF classic--May's Galactic Milieu Trilogy, which began with Jack the Bodiless and continued with Diamond Mask.