Fire in the Star

Claire Martinson has always depended on her older sister, Sophie, to take care of her, but now it's Claire's turn to protect her sister. On the trail of the last unicorn, Claire sets off on her own to make things right in Arden - the magical land she and her sister discovered when they climbed their great-aunt's chimney. But there are terrible forces working against her.
Queen Estelle has returned, and she will not stop until she has taken revenge on all those who have opposed her. Claire, Sophie, and their friends must convince Arden's four guilds of magic to set aside the past if they are to have any hope of a future. Because if the queen has her way, Claire and Sophie will never return home and the unicorns of Arden will be lost ... forever.
The thrilling third book in the series for fans of Cornelia Funke, Abi Elphinstone or The Chronicles of Narnia.

Kamilla Benko spent most of her childhood climbing into wardrobes, trying to step through mirrors, and plotting to run away to an art museum. Now, she visits other worlds as a children's book editor. She currently lives in New York with her bookshelves, teapot, and hiking boots. In addition to the Unicorn Quest trilogy, she is the author of the original Frozen novel that bridges the events of Disney's massively successful Frozen and Frozen 2.
www.kamillabenko.com
@kkbenko (Twitter)