But Mrs.

Mabel’s question cut straight through the comfort to the machinery underneath, because it followed the one thing that does not lie, which is motive.

Crimes, especially calculated ones, are not random.

They are committed by people who gain something, and if you want to find the person who did a thing, you do not start with who is capable of cruelty in the abstract — nearly anyone is, under the right pressure — you start with who profits, who is threatened, who stands to lose their whole position if events proceed as they should.

Follow the loss.