Molly's parents died when she was young, leaving her in the care of an emotionally abusive foster mother. One night, after growing tired of her constant insults, the young Molly killed her foster mother with a fatal injection of insulin (the woman having been diabetic). The police ruled the death a suicide and Molly gets away with her crime. She later becomes a high school teacher and began using her position to seduce male students. When her affair with a student was exposed, Molly fled the town and got a position as an English teacher at a different school.
At her new school, Molly instantly becomes infatuated with Danny Campbell, a baseball player and a student in her class. After learning about how Danny was struggling to keep his grades up stay on the baseball team, the conniving Molly began giving Danny tutoring and meeting him outside of school, eventually seducing Danny into having a sexual relationship with her.
Out of spite and jealousy, Molly began giving Danny's girlfriend Jamie Hall poor grades on her paper, no matter what she did to improve. Having already been getting suspicious of Danny's behavior, Jamie follows him after school one day and catches him making out with Molly at her home. Danny and Molly see her and she flees, while Molly tries to get Danny to stay under the promise of making sure Jamie wouldn't talk, but Danny left anyway, upsetting Molly. The next day, Molly gives Jamie an A on a paper she previously gave her a C on in an obvious attempt to bribe her silence, which Jamie tells her won't work. She talks to Danny and he agrees to ends things with Molly, meeting her in a parking lot late at night to tell her so. Molly is heartbroken and desperately tries to get Danny to reconsider, but he rejects her and calls her a freak. Upset and angered, Molly got into her car and ran Danny over, killing him. She then goes about framing Jamie for the murder by planting Danny's blood on her car bumper and the disposable cell phone Danny had texted her on to arrange the meeting in her glove box. She also buys a movie ticket in order to give herself a fake alibi. After learning of Danny's death, Jamie tells the police about his affair with Molly, but Molly lies to the police and says that Jamie had had a problem with her and that she would never hurt one of her students. This, along with the planted evidence, lead the police to arrest Jamie for Danny's murder.
Jamie's mother Lauren confronts Molly at school, where the two women get into a subtle standoff. Desperate to prove her daughter's innocence, Lauren breaks into Molly's car and finds the address to a shady mechanic where Molly got rid of her bloodied bumper. She finds this out, but the mechanic is unwilling to help Jamie. When Molly finds out what Lauren did, she has a breakdown in which she sees her younger self in a mirror, causing her to throw a rock at it. Still unable to prove Molly's guilt, Jamie snuck out of her house (despite being confined to house arrest with an ankle monitor) and confronts Molly at her house, secretly recording them on her phone. She lies to Molly saying that the police have her bloodied bumper, but Molly catches on to Jamie's plan and sees her phone in her pocket, smashing it. Jamie then taunts Molly, saying that Danny was only with her to get good grades and calling her pathetic. Molly freaks out and pulls a knife on Jamie, screaming at her that Danny wanted to be with her before she interfered. Jamie fights back, causing Molly to cut her face on the knife. Jamie tries to run, but is caught by Molly. As she prepares to kill Jamie, a detective bursts in and disarms her. Molly tries to act as though Jamie attacked her, but the detective had heard the whole fight. As he checks on Jamie, Molly hits him with a fireplace poker before trying to flee, but Jamie uses the detective's gun to stop Molly as the police arrive, arresting her. The final scene shows Molly in prison, watching a news story about her crimes on TV. When a teenage boy named John was interviewed about how he would react in Danny's situation, he replies that he would love it if "someone as hot as Ms. Matson" was interested in him. The psychotic Molly then sighs romantically while saying John's name over and over.
- Josie Davis also played main villainess Rachel Partson in the 2008 Lifetime film The Perfect Assistant and Paulette Bolton in the 2016 Lifetime film Backstabbed as well.
- Josie Davis also appeared as villainous terrorist Marta on NCIS, as well as the evil Serena from an episode of Chuck.