Beth Fleischer aka Liz was the villainess of "The New Year's Party", the 9th Super Chiller in R.L. Stine's original Fear Street series (published on September 9, 1995).
30 years prior to the events of the movie, Beth Fleischer was a Shadyside High student and the protective sister of Philip "Jeremy" Fleischer, who was shy and often the target of bullying. One night, during a New Year's Eve party for 1965, Jeremy was the victim of a cruel prank, leading him to run out in anger. Beth ran after him and got into his car as he sped away, despite Beth's pleads to slow down. After it appeared that they had hit a person on the road, Jeremy lost control of the car and crashed.
It first appeared that the siblings survived the crash. But after failing to get help from passing vehicles and a nearby house, Beth and Jeremy returned to the car. Inside, Beth found her and her brother's lifeless bodies, revealing that they had died and were now left as ghosts.
In 1995, Beth and Jeremy returned to Shadyside High, now going by the names Liz and P.J. Soon after their arrival, they become friends with protagonist Reenie Baker, along with her boyfriend Sean and the rest of their friend group (Greta, her boyfriend Artie, and Ty). Due to Greta taking an interest in the shy but attractive Jeremy, Artie becomes furious and devises a plan to get revenge on him at Reenie's Christmas party: he would have classmate Sandi Burke take "P.J." to the party as a date, kiss him, and then pretend to die to freak P.J. out. When Reenie warned Beth about the prank at the party soon after Jeremy and Sandi arrived, Beth became furious and stormed away, saying that Reenie had no idea what she had done.
When the prank occurred, however, Jeremy fainted and appeared to die from a heart attack, Beth having claimed he had heart problems. But after Reenie and her friends hid his body in the basement so they could figure out what to do, Jeremy snuck out of the house. Later on, the vengeful Beth and Jeremy planned to kill Reenie and her friends for revenge, believing them to be the same as the cruel teens whose prank led to their deaths. After leaving Jeremy's jacket in the Fear Street forest to make it appear he was missing, the evil Beth went about killing Artie's friend Marc Bentley and Sandi, doing so by twisting their heads around until their necks broke. Jeremy was present for both crimes, sadistically enjoying the murders. A few days after, Reenie went to Liz's house on Fear Street to apologize, only for her to coldly reject her.
But a few days after that, Beth sent a letter to Reenie, saying that they all had to stick together and was inviting her and her friends to a New Year's party she was holding at her house. When they arrived, Beth answered the door, having decorated the house in all black and donned a red velvet dress. She led the teens into a large room before locking the door and announcing her true motivation for holding the party: she had decided she wanted to kill them all at once instead of one at a time. She then revealed how she had killed Marc and Sandi, along with how she fully enjoyed it, before pulling out a carving knife and charging at Reenie. Sean managed to temporarily fight off Beth, but she managed to regain the knife and held it to his throat as Jeremy entered the room, pleased that Beth stopped so he could watch everyone die.
Sean then tried to stab Beth, but the act did nothing to faze the already dead villainess, who proved that she was a spirit by showing the group her and Jeremy's memorial page in the 1965 Shadyside High yearbook. They went on to reveal that they were going to kill them all as a way of getting revenge for their deaths, with Beth telling Reenie that she'd actually liked her and her friends before they pulled their prank on Jeremy. Ignoring the teens' pleas that they had nothing to do with their untimely demises, the evil Beth prepared to kill them when Ty stepped up, revealing that he was the person Beth and Jeremy struck and killed right before their accident and that he had come back from the dead to get his own revenge. The three then engaged in a fight before fading away into the afterlife.
- "The reason I gave this party is because I decided it would be easier to kill you all at once--instead of continuing one by one." (Beth's villainous reveal)