This is one of those novels that I think it may take some time to digest. It's beautifully written, and has a wonderful tone of darkness that feels as though the dawn is near.
The central mystery has to do with the sudden death of a British diplomat in Bonn. His wife and three children return to a remote island in the Outer Hebrides, believing that his death was accidental. The British government launches an investigation into his activities that implies he was a traitor who committed suicide rather than face charges. The widow retreats to denial and self-torture. Each of the three children is left to their own devices, to cope as they may. They each express their grief and fear in their own way, and they basically take out their pain on one another.
At the same time a circus bear escapes from its owner and becomes lost on the island. The bear is tame and is used to eating cooked food. It does not know how to forage.
The mysterious connection between the youngest child and the bear leads to a gripping climax and a surprise ending.
I liked the book a lot. I have the sense that this is the kind of story that will reveal itself to me slowly over time, in tiny snippets of recollection -- the way only a really good book can.
This is one to return to, in a few months or a year, to look again and perhaps see the layers of nuance in a different light.