Frank Galvin (Newman) is a down-on-his luck lawyer, reduced to drinking and ambulance chasing. Former associate Mickey Morrissey (Jack Warden) reminds him of his obligations in a medical malpractice suit that he himself served to Galvin on a silver platter: all parties willing to settle out of court. Blundering his way through the preliminaries, listening to his own enthusiastic expert witness, and visiting the paralyzed woman, Deborah Ann Kaye (Susan Benenson) in a vegetative state in the aftercare home, Frank suddenly realizes that perhaps the case should go to court: to punish the guilty, to get a decent settlement for his clients, and to restore his standing as a lawyer. To the astonishment of Mickey, Frank refuses a $210,000 settlement offer from the Arch Dioceses, and the hospital to settle the case.In his enthusiasm over his expert witness and his new found sense of purpose, Frank enters the bar where he usually hangs out and offers to buy everyone a drink. He notices a young woman, sitting at the end of the bar where he usually hangs out but she turns down his offer. The next night, after preparing for the case with Mickey, they see her at the bar again, and Frank decides that he is going to get laid. Laura Fischer (Charlotte Rampling) does agree to have dinner with him and ends up at Frank's apartment for the night. Later while Frank is trying to line up his witnesses, Mickey gives Laura Frank's background, almost being disbarred when he was going to report the jury tampering that the senior partner of his law firm was doing. The senior partners turned the tables, and Frank ended up getting arrested for jury tampering, then released when he agreed to not persist. But Frank lost his partnership as well as his wife who was the daughter of the other senior partner.Judge Hoyle (Milo O'Shea) calls Frank Galvin and the lead defense attorney, Ed Concannon (James Mason), into his chambers to get a settlement, but Frank refuses, so they set the trial for the next week. Upon learning of the settlement, Sally Doneghy (Roxanne Hart) the sister of Deborah Ann and Sally's husband, Kevin Doneghy (James Handy), who wants to get this over with so they can move to Phoenix and have $50,000 left for the lifetime care of Deborah Ann in Massachusetts confront Frank. But he tells them that the offer had been withdrawn in the Judge's chambers.When he tries to contact his own expert witness, Frank finds that Dr. Gruber (Lewis Stadlen) has left town for a several week vacation in the Caribbean, and cannot be reached. Frank first tries to get a postponement, then tries to get the settlement that had been withdrawn by Concannon, but both efforts fail.In a hurry, Mickey and Frank contact Dr. Thompson, as a substitute expert witness. But when Frank picks him up at South Station, he sees that Thompson is in his 70's and black. He puts him in a cab for Frank's own apartment, so the defense cannot get to him. Then Frank tracks down Maureen Rooney (Julie Bovasso) the only operating room nurse who is not testifying for the defense, who shuts the door in his face. When Mickey's mock cross examination of Dr. Thompson is going badly, Frank is ready to give up, but Laura Fischer who has been in those sessions at Frank's apartment convinces him to keep fighting. It gradually becomes clear to the viewer, but not to Frank that the defense firm knows Frank's every move, with someone tailing him to Maureen's house and the team doing background research on Thompson, even getting a black attorney to sit with the defense team.When the trial starts, Frank has a rough opening and the testimony of Dr. Thompson is shredded by Concannon, with the help of Judge Hoyle. Later, Frank realizes that Maureen Rooney is protecting someone, and also realizes that the admitting room nurse is not a witness for the defendants. Frank tracks Maureen to her church, and through a ruse gets her to tell him where Kaitlin Costello (Lindsay Crouse) is after telling her that he had talked with Kaitlin earlier that day. Meanwhile, Laura is given an envelope with a check by Ed Concannon, for her help in spying on the plaintiff team. Then, with Laura in the room, Mickey and Frank spend all of Friday night trying to track down a Kaitlin Costello somewhere in New York.On Saturday morning Frank notices his phone bill in the mail in the office. He goes again to Maureen Rooney's house and finds her phone bill in her mailbox. Then he tracks the phone calls to New York, and calls the number. Pretending to be from a nursing magazine, he learns that Kaitlin Costello has married, and now is Kaitlin Costello Price. He also learns where she is working on the weekend, and he catches an Eastern Shuttle to New York. After booking the Shuttle, he calls Mickey and Laura to let them know that he has found Kaitlin.Laura answers and insists that she meet Frank in New York. But while she is on the phone with Frank, Mickey looks in her bag for cigarettes, and finds the Check from Ed Concannon instead. Mickey quietly puts it away and laves to get a pack of cigarettes. Finding Kaitlin with kids in a playground, Frank tries to establish a false identity and makes small talk, but Kaitlin notices the Eastern airline boarding ticket in his coat, and Frank asks her for her help. Mickey finds Frank in New York outside of his hotel, just before Frank hooks up with Laura in the Sheraton Bar. Upon meeting Frank slaps Laura hard enough to draw blood and knock her down. When she tells everyone to let him go, Frank leaves without another word.At the trial on Monday, Frank finishes his examination of Dr. Robert Towler (Wesley Addy) the anesthesiologist who gave the general anesthesia to Deborah Ann Kaye that caused her to vomit into her mask. Towler states that anyone who would have given general anesthesia to someone who had eaten a full meal only an hour earlier was criminally negligent, but he pointed out that the admitting record had stated that Deborah Ann had last eaten nine hours before the operation.Then Frank calls his new witness, Kaitlin Costello Price, who testifies that she had admitted Deborah Ann Kaye and noted that she had eaten only one hour before the operation on the admitting record. Under heavy cross examination by Ed Concannon, she testifies that she has a photocopy of the record that proves that she had put one hour on the form, but that it had been altered by Dr. Towler who claimed that he had been too busy that day to read the record before he went into the operating room. Concannon is able to cite a precedent to Judge Hoyle to have the photocopy suppressed, and then after the testimony is complete, he asks Judge Hoyle to instruct the jury to disregard all of Kaitlin's testimony.However, after a subdued summation by Frank, the jury brings in a verdict of guilty, and asks if they can increase the amount awarded to the plaintiffs. On the way out of the courtroom, Frank and Mickey are being congratulated, and see Laura standing across the vestibule. When they turn back after turning away, she is gone. Later Laura calls Frank's office, and lets the phone ring for a long while. He is still looking at the receiver while it rings as the film closes.