Serilda and Gild attempt to break the curses that tether their spirits to Adalheid's haunted castle before the Endless Moon， when the Erlking means to capture one of the seven gods and make a wish to return his lover， Perchta， from the underworld。 But as the story progresses， it becomes clear he doesn't want just one god - he wants to capture all seven， and force them to bring down the veil that keeps the Dark Ones separate from the land of the mortals。 Serilda and Gild must try to thwart his plans， all while solving the mystery of Gild's forgotten name， freeing his younger sister who is trapped inside Gravenstone Castle， and trying to protect their unborn child。