Though many trilogies struggle through their middle entry, stuck in a sort of narrative no-mans-land between introduction and climax, Equinox, sequel to Zenith, is undoubtedly an exception. Certainly Equinox is a different sort of book to Zenith, but by no means a worse one, and it is by this difference that it performs so well as a second act.
In Zenith, Atreu's journey was very much about the physical; as he travelled across the surface of the Mountain, Strasser introduced its peoples, its cities and towns, and its landscape. Atreu's task was unambiguous. The Mountain was in sight, all he had to do was reach it.
Equinox, however, is a more complex work. Though Atreu has ascended the Mountain and witnessed enlightenment, his next task is about to begin, and is by no means as straight-forward. Confronted by the truth of his Zenith, Atreu must search deep inside himself to find the conviction to persuade the council who rule the Mountain to heed his words before it is too late.
Though there is no lack of intrigue, action, and excitement, it is in Equinox that Atreu truly develops most as a character. Naivety lost, he must learn the meaning of power and truth, and the responsibility with which both must be wielded.
Strasser is to be commended for not giving into the urge to rush a conclusion or meander pointlessly, but instead delivers meaningful character and plot development while continuing the same high standard of world-building, adventure, and wonder which make Zenith so enjoyable.
Highly recommended to fans of Zenith, and a worthy lead-up to Eclipse.