Heine Wittgenstein, a tutor so short he is constantly mistaken for a child, is summoned by the king of Granzreich to turn the four younger princes into viable heirs: Kai, Bruno, Leonhard, and Licht. Every tutor before him quit, defeated by the brothers' clashing temperaments, from Kai's social wariness to Leonhard's vanity. Stern and unflappable, Heine sets out to reach each prince on his own terms.