The title reflects how Kadance passes into the Kingdom of Glacian. She was raised by her grandmother, after her mother's passing. Her grandmother, Mayla, had come to this world from another world, accessible only through a portal hidden within a mirror. Kadance falls into the mirror portal with help from Titan. Titan has chosen Kadance to be his life partner. The mirror shatters, and she becomes a big part of this new world's kingdom.