I will not detail every technique of that manipulation, because it does not deserve to be laid out like a lesson; it is enough to say that it was aimed, deliberately and patiently, at convincing a grieving child that her own needs were a danger to the father she loved.

And I keep coming back to the deliberateness of it, because that is the thing that separates what Brenda did from an ordinary clash between a stepparent and a child.

Blended families are genuinely hard; adults and children thrown together after a loss really do rub against each other, and there is nothing sinister in the ordinary friction of two histories learning to share a home.

If that had been our story, I would have worked at it, patiently, for years.