The new A is stalking the girls, taunting them with secrets they want to forget, and this A is out for blood.

Aria, Emily, Hanna, and Spencer have been tormented for months by the latest stalker A. All of the girls secrets are out in the open and nothing left to lose except their lives.

Hanna, Spencer, Emily, and Aria want to move on and forget about Alison DiLaurentus but someone is trying to keep her spirit alive.

After their missing friend's body is found and another of their friends commits suicide, four former best friends live in fear of their secrets being exposed by someone who is stalking them via their cell phones.

High school seniors Aria, Emily, Hanna, and Spencer have all have their secrets. And their stalker 'A' knows everything. A has used their secrets to torture the girls, causing them to lose boyfriends, get kicked out of school, put into jail, and constantly hounded by the press. The Girls are determined to stop A once and for all. Because everybody knows the only way for two people to keep a secret is if one of them is dead.