Recently she had, little by little, become aware of an indefinable change in the man.

For one thing, he had grown more reticent.

At times, too, his reserve seemed to have something almost surly about it; under his cold composure a hint of something concealed, watchful, and very quiet.
Confidences she had never looked for in him nor desired.

It appalled her at moments to realise how little they had in common, and that only on the surface--a communion of superficial interest incident to the fulfilment of social duties and the pursuit of pleasure.

Beyond that she knew nothing of him, required nothing of him.