Anne Mountford, twenty-one, and her younger half-sister Rose live at Mount with their autocratic father and his second wife. The estate will eventually go to a distant male heir; but Anne's mother had brought a fortune with her when she married, and this is generally considered to be Anne's inheritance, though not tied up legally. Anne has been educated well at home, but was not allowed to attend Girton College, Cambridge.
When the novel opens Anne has just promised to marry Cosmo Douglas, a bright, well-educated barrister - though with little income and not of any family. Mr Mountford threatens Anne that if she goes forward with the engagement he will leave her mother's fortune to Rose. Though Anne does not realise it, Cosmo counts as much on Anne's fortune as he does on Anne herself. When Mr Mountford dies suddenly, both Anne and Cosmo are tested by the events which follow. And the new heir of Mount, Heathcote Mountford, is close at hand.