In suburban Nebraska, a group of partying high school teens jokingly dare their friend Charlie (guest star Marnette Patterson) to look into the mirror and repeat ‘Bloody Mary, Bloody Mary, Bloody Mary,” not knowing this will unleash a series of mysterious murders. Sam (Jared Padalecki) and Dean (Jensen Ackles) realize that Bloody Mary has the power to travel through all reflective surfaces when she is hunting a victim. Worried that teens are accidentally summoning Bloody Mary, Sam and Dean race to destroy the violent spirit before she can kill again.
The episode was written by Ron Milbauer and Terri Hughes Burton from a story by Eric Kripke, and directed by Peter Ellis.