Luna is sold into marriage to Sebastian, the Prince of Darkness, by her kingdom. Sebastian agrees to the marriage under orders from Queen Marguerite but expects to feel nothing. When their Binding Ceremony goes wrong and they are magically Tethered, unable to leave each other's presence, neither can hide from the other—or from the political storm that follows.

Luna is a thoughtful, quietly brave human navigating a world of vampires with no power of her own except her wits and her growing bond with Sebastian. Sebastian is defined by centuries of obedience to his Maker, whose grip he must break to be truly free. Their arc is a slow mutual discovery of trust in impossible circumstances.

Across four books, Luna and Sebastian move from reluctant prisoners of their Tether to genuine partners fighting against a queen who would destroy them both. The series escalates from gothic arranged-marriage romance to a deadly tournament, a prophecy, and an apocalyptic red moon that threatens the vampire realm of Eleyta. A fourth book shifts to the next generation.