This book diverges a bit more from the television series than the first two, but remains true to the form. The protomolecule has completed its work on Venus and the ring awaits us just outside the orbit of Uranus. But what is it? The combined navies of Mars and Earth are warily stationed nearby, probing and studying it. The book opens exactly as Series 3 did, with the ill-fated attempt of Maneo to make history by being the first human to pilot his ship, the "Y QUE" through the ring. Once again, the crew of the Rocinante become entangled in this new mystery.