The Firm is a 1991 legal thriller and the second novel by John Grisham. It was his first widely recognized piece of work, and in 1993, was made into a film starring Tom Cruise. Grisham's first novel, A Time to Kill, was successful but did not bring the author the attention of the general public.

Mitchell Y. McDeere is a law student who graduated third in his class at Harvard Law School. Mitch is married to his college sweetheart, Abby. His brother Ray is serving a prison term, and his other brother, Rusty, died in Vietnam.

Mitch has offers from law firms in New York and Chicago but eventually decides to join Bendini, Lambert and Locke, a small tax law firm based in Memphis. The firm seduces him by offering him a large salary, a lease on a new BMW 3 series, a low interest mortgage on a house, as well as paying off his student loans. Soon after he joins, his new colleagues help him study and pass his bar exam. At the firm, the first priority is for the associate to pass the bar exam.

Two of Mitch's colleagues die in a scuba diving accident in the Cayman Islands the week he starts at the firm. Mitch finds the deaths unsettling, but settles down, works hard towards his dream of becoming a successful employee of the firm. During a memorial service at the firm for the two deceased attorneys, Mitch notices plaques commemorating three other attorneys who died while working at the firm. Suspicious, he hires a private investigator, Eddie Lomax, an ex-cell mate of his brother Ray, to investigate the deaths of the attorneys.

Lomax discovers that all five of the deceased attorneys died under questionable circumstances: two in the diving accident, and the other three in a car accident, a hunting accident and a suicide, respectively. Lomax cautions Mitch to be careful. Soon after delivering his report to Mitch, Lomax is murdered.

Just as he passes his bar exam, Wayne Tarrance, an FBI agent, confronts Mitch. Mitch gradually learns from the FBI that the firm is actually part of the white collar operations of the Morolto crime family of Chicago. For years, the Moroltos have lured new lawyers from poor backgrounds into the firm with promises of wealth and security. By the time a lawyer is aware of the firm's actual operations, he cannot leave. No lawyer has escaped the firm alive, as the recent deaths of his two colleagues show. Mitch learns that his house, office and car are bugged. He and Abby are also routinely followed, making his meetings with the FBI dangerous. Pressure from both the firm and the FBI, who warns him he will regret not cooperating later on if he chooses to ignore them, force Mitch to make a decision quickly.

Desperate to find a way out and stay alive in the process, Mitch makes a deal with the FBI, in which he gets two million dollars and the release of his brother, if he collects enough evidence to indict the firm. Mitch tells Tarrance that he can obtain enough evidence to indict half the firm, but the information obtained through those indictments will prove the existence of an illegal conspiracy—giving the government the ammunition it needs to destroy the firm and the Morolto family. In order to do so, however, Mitch must disclose information about his clients, and thus end his career as a lawyer (though in truth, the attorney-client privilege in most U.S. states, including Tennessee,[1] does not apply to situations where a lawyer knows that a crime is taking place). Working with Lomax's secretary and lover, Tammy, Mitch begins to copy confidential documents and makes plans to deliver them to the FBI as planned.

Meanwhile, the firm becomes suspicious of Mitch, and with the assistance of "Alfred", a mole in the FBI, they discover Mitch's plan. Once Mitch learns of this, he runs from both the FBI and Mafia with his brother who escaped from jail, and his wife. He steals approximately ten million dollars from various bank accounts belonging to the firm.

Mitch manages to escape to the Caribbean with the help of Barry Abanks, a scuba diving business owner whose son died in the incident where the firm killed two lawyers, and George, a bank robber from Australia, while the FBI gets the evidence they need to bust the firm through a variety of documents Mitch and Abby copy from the firm. At the end, Mitch, Abby and Ray are quietly enjoying their newfound wealth in the Caribbean region.