The Business is a novel published in 1999.
Kate Telman is a 'level 3' executive in the Business, a vast business empire. During her sabbatical year, she comes to suspect that some of her colleagues are stealing from the organisation, and investigates.
The Business is a powerful (yet democratic) multinational commercial organisation, secretive (but not too sinisterly so), and very long-lived. It predates the Roman Catholic Church, and descends from a consortium of merchants in the Roman Empire which it even owned for sixty-six days (it hired a man to become emperor, but he lasted less than a month before being assassinated; a reference to the Emperor Didius Julianus). It is now considering taking over a country in order to gain a seat at the United Nations.
The story follows the heroine, Kate Telman, who is 38 and lusts after Stephen Buzetski, who is married. Starting from poverty, she has risen through the Business under the tutelage of her mentor, who adopted her at an early age, and her 'uncle Freddy', the man who invented the portable milk container (named the "chilp").