Allison DuBois may seem to most like a normal wife and mother of three, and she would be if it weren't for her visions and dreams of dead people that she's been having ever since she was a child. Allison is a medium - while awake she can read other people's minds and see dead people walking around, and while asleep she has visions from the past or future, usually involving the victim of a murder or a murderer. Allison must then interpret these often cryptic visions and encounters and use them to solve murders and crimes that usually only she can solve, due to her abilities.

Allison doesn't go at her crime-solving alone. She receives a lot of support from her husband Joe, who was at first skeptical of her abilities, in part because he's an aerospace engineer, but who now supports her and helps her out whenever he can. Joe and Allison must also raise their three daughters, while keeping them safe from possible dangers brought on by Allison's abilities. Joe and Allison have discovered that Ariel, the eldest daughter, and Bridgette, the middle daughter, both have abilities like Allison, though their abilities don't come into play as much as Allison's do. Marie, the youngest daughter, is only a few years old, but she too has recently shown signs of special abilities.

Allison works at D.A. Manuel Devalos' office, helping to solve crime and murder cases using her abilities. She often also works with Detective Lee Scanlon, whom she met last year and helped solve a crime he was personally involved in. Both D.A. Devalos and Det. Scanlon were at first very wary of Allison's abilities, but they have come to trust her through the many crimes and murders she has helped them solve. The only catch is that Allison must keep her abilities secret because if they were revealed, the courts and authorities most likely wouldn't take them as legitimate. As Allison gains the trust of D.A. Devalos and Det. Scanlon, she must continue to balance her supernatural life with her life at home, which she at times finds difficult, but manages to do with her husband Joe's help and support.