This accomplished novel puts readers in the disconcerting point of view of an elderly woman suffering from dementia who has a feeling her friend Elizabeth is missing, but has trouble remembering from one moment to the next what she's doing or where she is. Her frustrated daughter tries to help (and is a great character). Her past is clearer, and it too includes a missing person, the narrator's older sister. It's very well done, with fragmenets that come together satisfactorily in the end - but the strongest impact is in experiencing what it's like to have an unreliable short-term memory - more chilling than the gruesomest of thrillers.