He must have known or noticed something before he would speak upon such a subject.

And then again Mrs.Westmacott had herself said that she hoped to change her style of living shortly and take over completely new duties.

What could that mean except that she expected to marry?
And whom?
She seemed to see few friends outside their own little circle.

She must have alluded to her father.

It was a hateful thought, and yet it must be faced.
One evening the Doctor had been rather late at his neighbor's.