Set in the fictional town of Rosewood, Pennsylvania, the series follows the lives of four girls, Aria Montgomery, Hanna Marin, Emily Fields, and Spencer Hastings, whose clique falls apart after the disappearance of their leader, Alison DiLaurentis. One year later, the estranged friends are reunited as they begin receiving messages from a mysterious figure named A, who threatens to expose their deepest secrets, including ones they thought only Alison knew. At first, they think it's Alison herself, but after her body is found, the girls realize that someone else is planning on ruining their perfect lives.

When a brilliant bookstore manager crosses paths with an aspiring writer, he uses the internet and social media to gather the most intimate of details and get close to her. A charming and awkward crush quickly becomes obsession as he quietly and strategically removes every obstacle - and person - in his way.

After being dumped by her longtime boyfriend, a young woman must deal with her own imagination in order to literally and metaphorically re-enter the world of women, and rekindle the female friendships she left behind.