Frozen III: The Dark Mirror

This is a sequel to Frozen 2: the Snow Queen (which has to be read before you read this one). Set a few months after the last story, Anna and Kristoff prepare for their wedding, but Hans is back for one more attempt of revenge as he attacks Elsa in another, more cruel way as she is forced to deal with her inner demons, and make a great sacrifice. A bit darker than the last one.