I listened to Dan Sawyer's first entry in the Predestination series on his podcast, and was blown away by the quality and care with which he had laid out the plot and crafted the characters. This book is just as good.
The book is DEFINITELY not for those who like their stories simple, clear-cut, or "morally correct," though. Mr. Sawyer's vision of the future is far, far different from modern "good old American Values," and the degree of personal freedoms enjoyed by spacers, as the world's first society that has no traditions or taboos, is immense and may offend some.
If you haven't read Predestination, doing so is an absolute must in order to be able to be able to understand anything about this one. The degree of character development and the subtle undercurrents of hostility, trust, and loyalty that were developed in the first book are built upon to an astonishing degree in the second. Sawyer wastes no time introducing the story, so if you have read Predestination I recommend rereading it before starting this one.
Antithesis' sequel is even tighter, faster-paced, and multilayered and intricate than its predecessor. There were a grand total of two things in the entire book that struck me as unbelievable, which is up one from Predestination. As in the previous book, every character is an antihero, and the universe is constantly twisting their knives a little deeper. The plot is as thick as molten lead, and the writing is as smooth as chocolate. Sawyer has exceeded his own narrative ability, and I can honestly say that this book is one of the best pieces of writing (that I have read) that has been produced this decade.