The Firm by John Grisham
When Mitchell McDeere qualified third in his class at Harvard, offers poured in from every law firm in America. Bendini, Lambert and Locke were a small, well-respected firm, but their offer exceeded Mitch's wildest expectations: a fantastic salary, a new home, and the keys to a brand new BMW. It was his dream job - but it was to become his worst nightmare. Unravelling a complex trail of secret files, undercover surveillance, and millions of dollars of illegal mob money, Mitch stumbles across a shocking conspiracy and a horrifying truth: nobody has ever left Bendini, Lambert and Locke - and anybody who has ever tried has ended up dead.