I'm the King of the Castle is about the deep isolation and injustice possible in a child's world. Susan Hill is clearly aiming at fear in all its incarnations, but the only fear it really captures is that of being right in an adult world that is wrong; of being misjudged by everyone around you; of having nobody who shares your particular sanity.
Being a child in the circumstances of Charles Kingshaw is to live in a system that makes no sense; a world in which you need to speak out, but has no mechanism for your voice to be heard. The real fear is here. Forget the crow, the moths, the bully and the forest; think Franz Kafka.
I was drawn in to the helpless nightmare Kingshaw lives in at Waring, in time, despite the quite horrendous comma abuse throughout the novel. Every page is littered with twice as many commas as it needs, separating every minor pause of rhetoric, or failing to splice what should be separate items sufficiently. Opening a page at random -- 82:
He wanted to go wild, with the frustration of it, everything was against him.And:
By referring to it, he might manage to annoy Hooper, though he doubted even that, and in any case, he would never know for sure, Hooper kept a bland face.
Maybe they're not too bothersome on their own, but the sheer cumulative mass of them is overbearing (and there were far worse examples than on that particular page).
Still, Susan Hill can do no wrong in my eyes, for one reason. She has succeeded where almost every author I have read this year has failed, and got an ending spot on. This book ends at the final event of the inevitable chain. It does not have a change of heart; it does not undermine itself, out of authorially insecurity; it does try one clever step too many, out of authorial self-confidence.
Listen: this is what is missing in most books I read. Endings are zeniths, and endings are nadirs. Nothing else.