When Keziah's grandmother, Oma, is diagnosed with dementia, Keziah faces two choices: leave her family and move to New Winchester to care for Oma, or stay in New York City and allow her grandmother to live in a nursing home miles away. The dementia causes Oma to be rude and paranoid, nothing like the woman Keziah remembers. Each day becomes a greater weight and love a harsher burden. Keziah must keep Oma from wandering off or falling, and try to convince her grandmother to see a doctor as her eyesight and hearing fail, but Oma refuses to believe anything is wrong. Resentful of her hardships in New Winchester, Keziah finds herself drawn to Oma's ramblings about the Goat Children, a mythical warrior class. These fighters ride winged horses, locating people in need, while attempting to destroy evil in the world. Oma sees the Goat Children everywhere, and as Keziah reads the stories Oma wrote about them, she begins to question if they really exist.