Pretty Little Liars: Original Sins, Chapter One: Spirit Week

An enthralling season premiere. 20 years after tragic events almost tore Millwood apart, both the young and old generations must face the consequences of the past.

Imogen and her new friends' plot revenge on their common nemesis, while Karen and her twin sister Kelly hatch plans of their own.

As Millwood deals with the aftermath of recent events, Imogen uncovers secrets to unmask "A." Beasley gets closer to the truth, and Noa weighs her options.

After their punishment comes to an end, the girls cement their friendship when Imogen needs them most. Meanwhile, Noa finds herself in A's crosshairs.

Desperate to keep her mother's house, Imogen throws a Halloween party to raise cash. Unfortunately, the presence of an unwanted guest casts ruins the night.

As Imogen and Tabby dig into the mystery surrounding Angela Waters, Faran deals with the scars of her past.

As the Millwood carnival approaches, Mouse and Tabby struggle with secrets, and Noa notices Shawn isn't himself. Meanwhile, Imogen considers her baby's future.

The friends work together to uncover Imogen and Tabby's assailant during the Annual Thanksgiving Millwood High Blood Drive.

Despite coming clean to their mothers about "A," the friends find their troubles are far from over. Searching for answers, Imogen turns to her estranged father.

A tense and thrilling finale. With the anniversary of Angela's death approaching, an already vengeful "A" doubles down.