Darrow, the man known as the Morning Star and the Reaper, watched as his successful revolution against the Golds and dreams of peace turned into neverending war. Now cast out by the society he fought to create, he wages a bloody battle on Mercury that may risk transforming his cause into the kind of tyranny he once stood against… But as Darrow is on the brink of losing himself, other figures continue to rise. Lysander au Lune, the heir to the former empire, has returned to the Core with the aim to somehow unify the corrupt, competing Gold families and to fight Darrow in the skies above Mercury. Meanwhile, Mustang, Sovereign of the Republic and Darrow’s wife, works to support him while navigating treacherous political waters on Luna. Young Red refugee Lyria must fight or escape charges of treason, and thief Ephraim may be the only hope for rescue for Darrow and Mustang’s son Pax and his comrade Sevro’s daughter Electra.