In 1999, a group of friends is rocked by the sudden death of one of their own. Twenty-two years later, their daughters are pushed together by a mysterious foe.
As Millwood deals with the aftermath of recent events, Imogen uncovers secrets to unmask "A." Beasley gets closer to the truth, Noa weighs her options, and Tabby tries to retrieve some evidence.
Desperate to keep her mother's house, Imogen throws a Halloween party to raise cash. Unfortunately, the presence of an unwanted house guest casts a shadow over the celebrations.
As the Millwood carnival approaches, Mouse and Tabby each struggle with secrets, and Noa notices Shawn isn't himself. Meanwhile, Imogen considers her baby's future, and Faran confronts everything that's been plaguing her.
The friends attempt to get to the bottom of one mystery, while Imogen pursues answers to another. Then, a much needed girls' night prompts Sidney to confront her daughter about a long-held secret
Despite coming clean about 'A,' the friends find their troubles far from over, especially as the results of the group's clandestine blood drive push Tabby towards a new suspect.
As "A" doubles down, the friends must work quickly to uncover the link between Angela Waters' death, their mothers, and their mysterious foe - before it's too late.