It is prom time at Rosewood High School, except for Alison, Aria, Emily, Hanna and Spencer who have been banned due to "security" concerns. As the girls see this as the final humiliating blow to their high school careers, the girls' mothers try to make the best of a bad situation by offering a home prom in Spencer's barn. At first reluctant, the PLLs agree and try to make the best out of a bad situation. But one to never miss a formal, Charles has other plans in store to make this a night they will never forget. Meanwhile, Veronica, Pam, Ashley and Ella use prom night to touch base on everything that has happened to their daughters.
Never trust a pretty girl with an ugly secret. Gossip thrives amid the Mercedes-Benz, mega mansions, and perfectly manicured hedges in the exclusive town of Rosewood, Pennsylvania. Everyone has something to hide. Based off the book series of the same name, the series follows four estranged best friends Spencer, Hanna, Aria, and Emily who are reunited after their best friend and queen bee of the group, Alison, goes missing only to discover they are receiving messages from an anonymous "A" who knows all their secrets.