'One Dark Window' is indeed part of a book series called 'The Shepherd King' by Rachel Gillig. The story continues in 'Two Twisted Crowns', which picks up right where the first book leaves off. The series blends dark fantasy with gothic romance, creating a rich, eerie world filled with magic, curses, and political intrigue.
The first book introduces Elspeth, who carries a mysterious curse, and the sequel expands on her journey alongside new characters and deeper lore. Fans of atmospheric, character-driven fantasies will find the series compelling. The books are tightly connected, so reading them in order is essential to fully appreciate the unfolding plot and character arcs.