Three girls are playing Truth or Dare and one is dared to say “Bloody Mary” three times in front of the bathroom mirror. The girl accepts the dare and goes into the bathroom, and on the third statement, the other girls bang on the door. Their father goes down to investigate, unaware of a ghostly female figure reflected in the mirrors. He goes into the upstairs bathroom and sees veins beneath his eyes. His older daughter, Donna, comes home and sees a pool of blood beneath the bathroom door. She goes in and finds him dead.
Sam is dreaming of his girlfriend’s death when Dean wakes him up. They’re at the home of the dead father, Mr. Shoemaker, and go into the morgue pretending to be med students. When fast talking doesn’t work, bribery does, and they see that the corpse’s eyes were practically liquefied. Another bribe gets them a look at the police report, and then they talk with Donna at the funeral. The younger daughter, Lily, insists it was Bloody Mary but Dean reassures her. The brothers sneak into the upstairs to investigate but can’t account for why the father died instead of the daughter; the one who conjured Bloody Mary. Donna’s friend Charlie interrupts them, but they talk their way out of it.
Later, Charlie is driving home and talking on the phone to her friend Jill, who says “Bloody Mary” three times in front of her mirror, then pretends to get attacked. After Jill hangs up, the same figure appears in the reflections around her. As she undresses for bed, her reflection takes on a life of its own and starts bleeding from the eyes. Jill’s eyes start bleeding for real. Her reflection accuses her of killing a boy as Jill dies.
Charlie gets hold of them and after agreeing to help, lets them into Jill’s bedroom. Using first heat-sensitive cameras and then a black light, they find a handprint and the words “Gary Bryman.” They check it out and find that Bryman was an eight-year-old boy, killed two years ago; hit by a car Charlie identifies as Jill’s. Another black light trace reveals the name, “Linda Shoemaker”, the dead man’s wife who committed suicide. Dean runs a nationwide check of Mary’s that committed suicide, but Sam wonders if Bloody Mary is punishing people who had secrets involving murder. They find an unsolved murder of a Mary Worthington in Fort Wayne, Indiana, with a similar handprint and whose eyes were cut out.
Fort Wayne, Indiana
The brothers talk to the detective who investigated the case, who reveals the letters “TRE” were written at the crime scene. A local surgeon named Trevor was the primary suspect, and Mary was going to tell his wife they were having an affair. Mary’s body was cremated and the mirror given to the family, so they go to investigate.
Meanwhile, Charlie tries to convince Donna of what’s going on while they’re in a school bathroom. A skeptical Donna intones “Bloody Mary” three times and nothing happens, but as Charlie leaves, the ghostly figure appears in nearby reflections. Later in her room, she sees Mary in her compact and freaks out, smashing windows.
The brothers have no luck getting the mirror from the brother – he sold it to a store in Toledo. They figure Mary’s soul is trapped in the mirror and they have to smash it. Charlie calls, and they take her to their hotel room after covering all the reflective surfaces. They confront Charlie with the secret she’s holding back, and she reveals that she had a boyfriend she broke up with, who killed himself over her. The brothers figure it’s enough to draw Mary’s ire, and Sam wonders if smashing the original mirror is enough. Dean confronts Sam with the fact that he believes he was responsible for his girlfriend’s death, and Sam reveals that he has his own guilty secret – but he’s not going to tell so that they can lure Mary to him.
Dean reluctantly agrees and they break into the store where the mirror is – problem is the store is filled with mirrors. They start looking, unaware they have triggered a silent alarm. Sam finds the mirror and then chants “Bloody Mary” three times, as he prepares to break the mirror.
The police arrive outside. Dean goes to delay them just as Mary starts appearing in the mirror. Sam starts shattering each mirror she appears in, but his eyes start to bleed out as his reflection blames him for killing Jessica. Dean punches out the police and runs back inside while Sam’s reflection accuses him of dreaming Jessica would die in fire before she died. Dean gets there just in time to shatter the mirror with Sam’s reflection, but Mary crawls out of the shattered mirror and comes at them, causing both their eyes to start bleeding. Dean manages to grab a mirror and show her her own reflection; her own image accuses her of her many murders and she disintegrates, then Dean shatters the final mirror.
The guys drop off Charlie. Sam advises she let go of her guilt, and Dean suggests Sam do the same. As they leave, Dean asks what the secret was, but Sam refuses to tell. As they leave, he briefly sees a ghostly figure of Jessica, but she disappears before he can get a second look.
Warning : May Contain Spoilers.