Jack and Lucy's adventure continues as the two friends travel through an interdimensional portal to another world and pledge themselves to the Apollonians' humanitarian cause. However, they have yet to find the Risa Star. As their quest to find Alex and defeat the Darkness unfolds, their journey takes them to alien worlds that uncannily parallel their own—an arctic mountain range, a city in the throes of industrialization, and a forest with inhabitants who are literally a part of their environment. But Jack and Lucy aren't the only ones looking for the Risa Star. The Cult of Dionysus draws ever closer to the completion of its super weapon and threatens to bring about carnage on an unprecedented scale. Meanwhile Alex remains the Emperor's prisoner, struggling against the increasingly inviting pull of the Darkness.
After thwarting the Cult of Dionysus and with the city of Nexus in ruins, all that remains for the Apollonians is to find the final Shards of the Risa Star before the Cult can use it to wreak havoc on an astronomical scale—but in this final installment of the Seven Stars trilogy, Jack Lawson and his allies face unexpected challenges. They are worlds apart; some battling old enemies in a desert fortress, and others in a formerly prosperous city-state that is slipping into totalitarianism. All the while, the pieces of a greater puzzle have been moving into place and a trap has been laid, and Jack must confront a truth that threatens to destroy everything.