Isaac Asimov story, Reason, which so beguiled me as a child. Klara is an AF - or "artificial friend" - an android companion who begins this novel gazing from the window of a trendy shop hoping that someone will buy her. She's an intelligent, observant machine, powered by the light of the Sun, but there's much of the human world she doesn't fully understand and readers must be active participants, filling in gaps in her knowledge or puzzling out what's really happening.
We understand that the small girl who smiles at Klara through the glass shop front and promises to come back and buy her may never return. We understand that a character with a serious illness may never recover. We understand that Klara goes to live with a traumatised, grieving family who don't always behave logically. But we also understand that Klara acts out of genuine concern to do right by these people. All our sympathies are with her, even more so than with the sick child at the heart of the story.
There are some disturbing ideas here: the genetically edited, "lifted" children and the social underclass then left behind; the idea of machine copies of the dead who can live on as comfort to their families; the haunting hints about the cruel treatment inflicted on AFs sold to other families; the understated cruelty of old AFs being left on the scrapheap to succumb to their "slow fade". But really this is an unconventional love story - nominally about two children whose lives are diverging, and actually about the devotion shown to them by their keen-to-please servant.
Then there's Klara's relationship with the Sun, her power source, who she assumes can power others, too - and is sentient and listening. I'm not sure how I feel about the ending of the book, which implies Klara might be right, that the Sun can intervene. It feels dissatisfying because, for once, there's no alternative to the meaning Klara applies here - there's no potential alternative reading that we can infer, other than lucky coincidence.
The coda, with a figure from Klara's past returning for one last conversation, is much better handled - poignant, sad, and with Klara still trying to make sense of human behaviour and her own complex feelings.