Celine is 68, blue-blooded, Sarah Lawrence grad, an apartment under the Brooklyn Bridge, a cigarette habit that gave her emphysema, and a better record finding missing people than the FBI. She takes cases about lost families because of a hole in her own. A young woman named Gabriela comes to her about a father who vanished twenty years back — a National Geographic photographer shooting grizzlies near Yellowstone, car found empty outside the park with bear tracks and a lot of blood, body never recovered. So Celine and her husband load a camper and drive west into country nothing in her life prepared her for, dragging an oxygen bottle, and figure out fast that somebody is following them and wants the case left shut. Heller based her on his own mother.