They understood one another to perfection.

Lady Charlotte was as hard as nails, and Sarah was harder.

Sarah had never been known to cry.

She had bitten the fingers of one of her nurses through to the bone, and had stuck a needle into the cheek of another whilst she slept, and had watched, with a curious abstracted gaze, the punishment dealt out to her, as though it had nothing to do with her at all.

She never lost her temper, and one of the most terrible things about her was her absolute calm.