All is not well with the arrival at the Bentinck of Marcus Carrington, a handsome and very talented financier who has had a remarkable success in the City. The man is also the son of one of Major Smith-Barton's long ago loves. Louisa and Major Smith-Barton enthusiastically decide to invest all of their money in a South African diamond mine venture promoted by Carrington, but with disastrous results. Another problem arises when Louisa becomes quite smitten with the young man. When he shows an interest in Mary at the Servants Ball - where servants become the guests and the guests take on the role of servants - Louisa explodes, drowning her in expletives and leaving her no choice but to resign.
—garykmcd