Alice Hart is a secondary villainess from "Don't Stay Up Late", the 2nd book in R.L. Stine's revived Fear Street series (published on April 7, 2015).
Alice was the sister of Brenda Hart and acted as an aid to her plot to create a half-human/half-demonic creature. Prior to the events of the book, there were three failed attempts to create sure a monster, and the rejected spawns were kept in cages in Alice's basement. Alice acted as a homeschooling teacher for Harry, the successfully created monster they were in possession of prior to the start of the book. Also aiding the plot were Brenda's therapist friend Dr. Shein and her cousins Nate Goodman (Lisa's boyfriend) and Saralynn O'Brien (Lisa's best friend).
When Brenda had teenager Lisa Brooks begin babysitting Harry, Alice acted as support for the teen (her having recently lost her father in a car accident) and acted affectionately to her "nephew". Once while at Alice's house, Lisa heard the creatures down in the basement, but Alice claimed the noise to be her cat. When Lisa began noticing odd things about Harry, Alice lied and told Lisa that he had neurological problems that Brenda didn't like to talk about.
Later on, though, after growing suspicious, Lisa investigated Alice's house and discovered the monstrous creatures in her basement. But by the time Lisa had the police at the house, Alice had hidden the creatures away to make Lisa appear delusional. After Brenda unsuccessfully tried to kill Lisa upon discovering Harry's secret and Dr. Shein was arrested, Alice fled her home and avoided apprehension for her role in the twisted plan. Harry later resurfaced at a daycare center Lisa was working at, but it is unclear what became of Alice.