The ten thousand doors of January / Alix E. Harrow.

In the early 1900s, a young woman embarks on a fantastical journey of self-discovery after finding a mysterious book in this captivating and lyrical debut. In a sprawling mansion filled with peculiar treasures, January Scaller is a curiosity herself. As the ward of the wealthy Mr. Locke, she feels little different from the artifacts that decorate the halls: carefully maintained, largely ignored, and utterly out of place. Then she finds a strange book. A book that carries the scent of other worlds, and tells a tale of secret doors, of love, adventure and danger. Each page turn reveals impossible truths about the world and January discovers a story increasingly entwined with her own.