Allison DuBois (Patricia Arquette) is a strong-willed mother of three, a devoted wife and law student who has had the gift of being able to talk to dead people, as well as foresee events, and witness past events in her dreams. When she begins working for the Phoenix District Attorney, Devalos, she has a dream which relates to a murder in Texas, which convinces her boss and others working in the DA's office that her gift is real.
The real challenge is initially convincing her boss, D.A. Devalos (Miguel Sandoval) — and subsequently the other doubters in the criminal justice system — that her psychic abilities can give them the upper hand when it comes to solving violent and horrifying crimes, whose mysteries often reside with those who lie beyond the grave. Information on certain people or crimes come to her in dreams or in cryptic visions which often do not mean what they initially suggest.
Allison is often accompanied by Det. Lee Scanlon (David Cubitt), who initially did not believe in her "gift." Allison often bends the rules of the law when she is determined to stop a crime about which she's had a vision. Additionally, Allison has helped and been helped by Captain Kenneth Push of the Texas Rangers (Arliss Howard), who is the first law-enforcement person to whom Allison revealed her gift and Cynthia Keener (Anjelica Huston) of AmeriTips. In season four, it was revealed that Cynthia had a daughter who was missing. Alison's dreams revealed to Cynthia that her daughter was dead. Cynthia made a choice to kill the murderer of her daughter and do time in jail. Keener later appeared in season five to help Alison on a case for the D.A. At that time, it was said that Cynthia has a couple more months to go before she is eligible for parole. In the season five finale, Allison discovers that she has a brain-tumor located on her brainstem. In order to prevent apparent murders in the future, Allison risked her life as she postpones the critical surgery to put a case to rest. During her operation the tumor was successfully removed, but Joe is told that Allison is in a comatose state, with doubts of her survival.