In many respects, this book feels like a fairy tale - one of those Irish ones, where fairies are all but nice. Also, it seems to contain bits of string theory now and again - which might be almost counted as magic.

The story is told by a nameless man who returns to the home of his childhood after a death in the family and begins to remember events he hadn't even known had taken place. They are centered around a girl he new as a young boy, Hetty.
Gaiman manages to show how differently children see the world - how willingly and unquestioningly the young boy follows Hetty into her world of mystical and magical creatures, dangers and adventures. Even when he finds out that Hetty is no quite as human as he is, he does not see this as a problem in their friendship.
For Hetty's family, Gaiman seems to have taken up the motive of the Triple Goddess: the maid, the mother, and the crone. They are a guardian force, living on the edge of this world and other worlds, seeing to it that everything stays where it belongs.
During the story I sometimes wondered whether the fantastical elements were the boy's way of explaining what was inexplicable for him as a child - a very adult point of view, and mistake, I suppose.
For in the very end the reader learns that it has been quite the other way around: The adult has explained away his childhood experiences as fantasies about events he could otherwise not come to terms with as a child, and he has even managed to forget (again and again) that he did remember the truth which was only pure and simple if you accepted the fantastical as part of the real.