Oliver Lambert was an antagonist in the John Grisham novel The Firm and the movie based upon the novel.
As a young man he joined a new Memphis area law firm which would eventually become known as Bendini, Lambert & Locke. The firm officially concentrated on tax law and accounting, however in reality they were a branch of the Chicago Morolto organized crime family, with the founder Anthony Bendini being the son-in-law of the old man Morolto. Lambert was drawn into the firm's criminal activities, which made up 75% of the firm's business.
Lambert rose through the ranks of the firm, eventually becoming a senior partner and the firm came to bear his name. Lambert and his partners would recruit young, impoverished attorneys and offer them jobs with large salaries and fantastic benefits. They would eventually draw the attorneys into their criminal activities, and before too long the attorney would be too compromised to talk about their work.
In the early 1990s Lambert and the other senior partners became aware of a recent Harvard Law School graduate Mitch McDeere. Lambert and the other partners offered the young financially strapped attorney a job with a large salary and other tangible benefits. McDeere accepted but soon became suspicious of the firm, especially with the deaths of two of the firm's attorneys right before he started his new job.
McDeere soon learned the truth about the firm, and that the five men who tried to leave the firm before him all died by the orders of firm hitman Bill DeVasher. McDeere was able to escape from the firm and provided evidence to the FBI. The FBI was able to use the evidence McDeere provided to take down the firm. Lambert and the other senior partners were charged with crimes, along with the other attorneys at the firm as well as several retired attorneys.