Here was confirmation, if further confirmation was needed.

Dust on chairs and tables and sofas in the house in which his mother was present.
Impossible! Such a thing could not occur with her there.

It was not the white dust of the road or fields, but the black dust that gathers in closed chambers.
He went up to his mother's room, and, opening one of the shutters a few inches, let in a little light.

It was in perfect order.

Everything was in its place.