Mena Harling learns shoddy maintenance caused ThriftJet crashes, one in which her brother died. Then a whistleblower is murdered, a note left by his corpse—Too risky to fly; deny that, you’ll die; I’ll watch your tears dry; your last sigh’s my high. Aether. And TOETIFTSA, who desecrated Nora Kelly’s church, continues killing Christians, leaving a note—Christian fundamentalism is not a righteous pursuit. So Maxine Kordell, Nora, Willi Mayers, and Haley join Mena. When Aether murders Cluster members, The Tracer asks for help, and reveals The Cluster killed Will Rogers, Amelia Earhart, and Glenn Miller. Then Aether attacks Dulles Airport and other iconic aerospace sites, as TOETIFTSA causes the crash of a plane carrying Christians, then tries to murder Nora. So Mena seeks help from a notorious serial killer, a psychiatrist living in Italy, who will profile Aether if the team agrees to a favor. Finally, events push Mena to become the determined protector of certain sociopaths just rewards.