Bull mounts the defense of an idealistic state judge, Judge Duggan, who's on trial for obstruction of justice after she helped a trial witness evade federal arrest in her courtroom. During voir dire, Benny looks for jurors who believe the law is open to interpretation and that Judge Duggan broke the law to uphold courtrooms as sacred spaces within the justice system.
Bull faces the unknown in court when TAC represents a train engineer with no memory of the fatal crash he allegedly caused, due to a brain injury he sustained in the collision. Knowing his client's missing memory will help the prosecution's allegation of human error, Bull searches for jurors who will place shared blame at the feet of the engineer's corporate employer.
Bull assists in the murder trial defense of an old friend, an in-debt professional gambler accused of killing her wealthy father to gain her inheritance. Knowing their client had a complicated relationship with her father, Bull and Benny enter into voir dire looking for jurors who sympathize with dysfunctional family relationships.
Bull is hired by a doctor, Samir Shadid, who's accused by the Manhattan U.S. attorney of bribing his way into college, just as Bull's ex-wife, Isabella, is due to give birth. As Bull waits for Izzy to go into labor, he contends with the trial's national news, due to its connection to a high-profile college admissions conspiracy case.
Bull and Benny represent a couple being sued by their baby's biological father for custody after a fertility clinic mistakenly used the wrong man's sample. As family court cases are solely decided by a judge, Bull and Benny worry about their best strategy at trial without a jury for TAC to analyze.
Chunk's friend, Reggie, an elite boarding school's counselor, asks Bull to help the parents of an athletic scholarship student bring a wrongful death suit against the school after the teen dies suddenly while training
Bull looks to select jurors who can empathize with an individual's need for personal privacy when he helps Marissa's friend, Stephen, sue a notable philanthropic businessman for abusing him as a child.
Bull and the TAC team take a difficult pro bono murder case before the holidays and realize it will take a Christmas miracle to win, as the presiding judge has a grudge against Bull. Also, Marissa pushes for an office Christmas party, and Taylor embarks on a new romance.
Bull represents a large insurance company and its clients, married pizzeria owners who are being sued for negligence by a teenager who was injured while climbing their rooftop signage. As the trial gets underway, Bull realizes the case has no clear winners, as the small business owners could lose their livelihood, the plaintiff may never walk again and the insurance company refuses to settle.
Bull and the TAC team question whether they have a solid defense when they represent wealth manager Rachel Elliot who's on trial for her husband's murder, which she claims to have no memory of due to an alcohol-induced blackout. When Rachel's reputation for aggressive behavior threatens to hurt them in court, Bull avoids jurors with "rage bias," an inherent dislike of people who can't control their emotions.
Taylor becomes personally invested in having Bull help a dancer, Jessica, bring a civil suit against a real estate mogul who assaulted her at a gentlemen's club when the district attorney's office refuses to pursue criminal charges. As the TAC team faces an uphill battle in court due to the defendant's fame and popularity, Bull aims to select jurors who believe privileged people don't deserve special treatment.
Bull helps a famous social media influencer, Sadie Washington, take her father to court to overturn his legal guardianship over her empire, which he was granted after the young mogul suffered a public mental breakdown. To counteract any jury bias Sadie faces due to the public's perception of her mental illness, they aim to select jurors who believe in giving people second chances.
Benny's previous career with the District Attorney's office comes into focus when Chunk, working with his law professor's legal clinic, aims to get a new trial for Eddie Mitchell, a man he believes was wrongfully convicted of triple homicide by a prosecution team that included Benny.
Bull sees a visionary whereas the federal government sees a con woman, when he helps the defense of a charismatic entrepreneur, Whitney Holland, who's accused of defrauding investors in her seemingly groundbreaking water filtration system company. As the trial gets underway, Bull focuses on selecting jurors whose belief systems allow them to see his client as a dreamer who never meant criminal intent.
In the Season 4 premiere, Bull prepares for fatherhood, while his work at TAC suffers without his top attorney, Benny, who quit in reaction to Bull's romantic reconnection to his ex-wife and Benny's sister, Isabella. In addition, the team faces a difficult time in court as they mount a defense for a young bartender on trial for involuntary manslaughter.