Corrupt politicians, frenzied nationalists and other belligerent forces, and extremist groups continually threaten the fragile peace that separates neighboring nations Ostania and Westalis. Despite their schemes, the famed spy and master of disguise known as "Twilight" carries out perilous assignments one after another, hoping that no child will ever endure the terrors of war.
In the lively Ostanian metropolis of Berlint, in its bustling streets, Twilight assumes the identity of "Loid Forger," a respected psychiatrist. Yet his real aim is to collect information on the prominent politician Donovan Desmond, who only sporadically appears in public at his sons" school: the esteemed Eden Academy. By recruiting the single city‑hall clerk Yor Briar to pose as his wife and adopting the inquisitive six‑year‑old orphan Anya as his daughter, Loid executes his elaborate scheme. He enrolls Anya at Eden Academy, where he expects her to thrive and grants him a chance to meet Donovan without raising suspicion.
Unfortunately for Loid, even someone of his skill struggles with the role of a caring father and husband. And just as Loid conceals his true identity, Yor—an underground assassin dubbed the "Thorn Princess"—and Anya—a telepathic child who can read minds—have no intention of revealing their own secrets. Though this seemingly perfect family is built on deception, the Forgers gradually discover that the love they share eclipses everything else.