As the Winter solstice blankets the Pembrokeshire landscape in an otherworldly glow, sisters Kit and Libby are drawn to a mysterious white tower to test a prophecy they have heard talked about. But when the magic of the tower causes Libby to vanish, they find themselves caught in a mystery that takes them in to the deep past. Libby has been erased from the world - her laughter, her presence, even their mother's memories of her have all disappeared. The world has rewritten itself, leaving Kit to navigate a reality where her sister doesn't exist. Determined to unravel the enigma surrounding her sister's disappearance, Kit joins forces with a local boy named Story. Together, they journey through a world steeped in ancient folklore, on a quest fraught with danger beyond their wildest imagination. The race is on to find a sister, help heal a cosmic wound and put the world back on its proper course. This lyrical and beautiful novel explores themes of responsibility both personal and political and the importance of love and friendship to make good in the world.