Melinda has the ability to see and communicate with ghosts. She moved to Grandview after she married Jim Clancy, a paramedic who knows of her ability. She had always been able to speak with the dead, or "earthbound spirits" as her grandmother (with whom she shared this ability) called them. Her mother, Beth Gordon, possesses the same gift, although she denies it. When Melinda was a little girl, her father was killed, thus showing that he never walked out on his family.
Melinda and Jim moved to the small town of Grandview where Melinda opened a small antique shop, named "The Same As It Never Was". She met and became friends with Andrea Marino, who came to share management responsibilities of the store with Melinda. Eventually, Melinda gained enough trust in Andrea to tell her about her ability.
Melinda is at least a fifth-generation medium (as her great great great grandmother, Tessa, was also a ghost whisperer). She is able to communicate with the spirits of those who are dead. She can see and speak with the earthbound spirits that reach out to her for help. She then helps them to cross over, either by speaking to loved ones or by doing things for them which they died before they could do/finish, giving them peace.
As a result of her abilities, Melinda often receives visions of things concerning the ghost(s) she is trying to help. For example, in the first season finale, Melinda kept receiving messages from ghosts on a plane that hasn't crashed yet. In another episode, her powers transported from Grandview to a rainforest. In the second season finale, she sees people staring at her, looks out her window and sees that her house is under a large body of water and that a boat is sinking, is transported to a tunnel, and sees a large bridge in the sky with cars falling