Alone

In 1999, a deadly Y2K rave leaves a group of friends forever changed. Twenty-two years later, the life of pregnant 16-year-old Imogen Adams is rocked by the sudden death of her mother, Davie -- and the fallout of a fight with her former best friend, Karen. Then, as Millwood High's Spirit Week approaches, Imogen and a group of fellow outcasts are targeted by a shared enemy.

After receiving a series of increasingly disturbing texts, Imogen and her newly-formed friend group -- Tabby, Faran, Noa and Mouse -- plot to end Karen's reign of terror. Later, Imogen finds herself in an unexpected position just in time for the Spirit Week dance, while Karen and her twin sister Kelly hatch a payback plan of their own.

In the wake of Spirit Week, Imogen unearths long-buried truths on her path to unmask the mysterious "A." After Sheriff Beasley closes in, Noa, Faran and Mouse weigh their options, while Tabby works to recover vital evidence.

With her mother’s house now on the market, Imogen consults the supernatural for answers. After being forced to spend time with Kelly, Faran notices a string of peculiar coincidences -- and enlists Henry for help testing her hypothesis. While shooting her latest short film, Tabby remembers a harrowing trauma and Noa comes face-to-face with a terrifying foe.

Unwilling to part with her mother's house, Imogen throws an epic Halloween rager to raise some cash to save it -- and enlists her friends to help. At the party, Faran puts her Kelly theory to the test, while Mouse wades in dark waters tied to a mysterious core wound. Later, Tabby confronts Tyler and Greg for their toxic behavior.

After bonding over shared trauma, Imogen and Tabby take a road trip to Rosewood, where they double down on their efforts to uncover the truth about past events. Meanwhile, Noa attempts to help her mom, Mouse goes on her first date and, armed with a tip from "A," Faran works to heal old wounds.

As the annual Millwood carnival approaches, a long-held family secret causes increased tension between Mouse and her mom, Elodie. Meanwhile, Imogen forges an unexpected connection during a health class assignment that hits close to home, Tabby hatches a new plan and Faran finally confronts her chronic pain -- and her mother.

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 to their mothers about "A," the friends find their troubles are far from over. In the search for answers, Imogen turns to her estranged father for help, while Tabby considers an unexpected suspect. Then, Mouse deals with the aftermath of a lie, as Faran attempts to protect Kelly from an increasingly unhinged Sheriff Beasley.

With the anniversary of Angela's death approaching, an already vengeful "A" doubles down. As Tabby and Imogen work to confirm a hunch, the members of the group confront their mothers about what really happened on New Year's Eve 1999 -- and how it led to them being tormented by a vengeful masked assailant in the present.