A mother and her three daughters — romantic Bee, sensible Evie, and child of nature Daisy — occupy the titular glass building, which has been completely sealed off to protect its occupants from a dementia-inducing toxin called the Shred that’s poisoning the air outside. Fearful of becoming like the lost souls who wander the abyss outside, the family keep a grasp on their past by performing sacred rituals. When Bee breaks the rules and lets an injured stranger into their midst, the family dynamic...