All Hail the Queen is the first book in the Anna & Elsa: Sisterhood is the Strongest Magic series.
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Now that the castle gates are open, Anna and Elsa are thrilled to be finally getting to know their kingdom. Anna bubbles with enthusiasm for all the things to do and the people to meet in Arendelle, and Elsa loves using her magic to help the town. But sometimes even a queen needs a day off.