Conor imagines a monster of a yew tree – the old tales of "The Green Man" come to mind – but when it threatens him one night, he says it has nothing on the nightmare he's already living through – the worst thing he can imagine is already happening to him. Over the course of the story, we find out what that nightmare is, and why Conor fears it.
The thing is, Conor knows his mum is dying. He's known his mum has been dying for a long time, and watching it fills him with pain, a pain he wants to stop – but the only way would be if she dies. Filled with guilt, Conor both strikes out and collapses into his own world.
Compared to that, the Yew Monster has got nothing. But the Yew Monster is wise enough to know that Conor wants his own pain to end. Watching his mum suffer is as bad for him as it is for her.
This book sucker punched me. It starts off with what seems to be a simple story, almost a children's book level. It quickly evolves into a more complex tale of survivor guilt and the terrible burden of watching someone die by inches. The terrible guilt of just wanting it to be over.
Powerful stuff from a book that seemed so simple.