Grief is a powerful thing. For Jim Hawkins, losing his father was so traumatic that he almost killed himself.
Guilt is also a powerful thing. Indirectly, it led to Hub's death, though he had some help. The cause of that guilt is not something that Jim has ever wished to pursue. It was bad enough to have watched his father being eaten up and diminished over a period of months to the point where he simply vanished, no body ever being found. Considered as a wasting mental breakdown it could barely be borne, and Jim really doesn't want to consider it any other way.
Ruth Rose has other ideas. They are suspicious ideas, because 16 year old Ruth is a little crazy if she forgets her medication, and she has spent time in a mental institution. But Rose is persistent and compelling, and for Jim there is something satisfying about her conviction that his father didn't actually chose to vanish, to desert his wife and son - that he was murdered.
The catch is that she insists the deed was done by her stepfather, the Reverend Father (he had his name legally changed from Eldon) Fisher of the Church of the Blessed Transfiguration.
Father had been a handful when he was a kid, back when he and Hub had played pranks on people, but that had changed after another friend had died in a fire during his senior year in high school, and his personal transfiguration had made him a new man, one who now inspires his flock and drives about doing good deeds in a van most call the Godmobile.
It's an awkward time to begin to be suspicious, to sift through back issues of the local paper, to try to figure out what is meant by the mysterious "Tabor" that keeps turning up in Father's private prayers. It gets even more awkward when Ruth Rose tapes those prayers with their strange garbled, childlike tones and slips the cassette into the church's sound system during a service. Still more awkward when it becomes clear that Father controls the church benevolent fund which is going to loan Jim's mom enough money to get the farm out of debt.
The Boy in the Burning House starts off slowly enough, and the revelations pile up in a leisurely fashion, but the last half of the novel is pedal to the metal action, beginning with Ruth Rose running away and coming to the Hawkins house to hide. Everything comes together very quickly and intensely at the end, answering all the questions.
It seems typical of Wynne-Jones young adult books that even the people you would have to call the bad guys have a little something that makes you feel for them. In the case of Father Fisher, he seems to be in the grip of a powerful religious driven delusion about life and his role in it. The setting of the novel is pure Perth County, where the author lives, but he is quick to note that none of the clergy around there are anything like this man. Thank God for that.