"A Face Like Glass" is a fantasy novel by Frances Hardinge set in a unique underground city called Caverna, where the inhabitants create intricate masks to express their emotions and identities. The story follows a young girl named Neverfell, who has a mysterious ability to show her true feelings on her face, making her an anomaly in this mask-wearing society. As Neverfell navigates the complexities of Caverna, she uncovers dark secrets about the city's ruling class and the dangerous world of cheesemaking, which plays a central role in the plot. The novel explores themes of identity, freedom, and the nature of truth in a richly imagined setting.