The series premiere of a drama about four estranged friends reuniting because of mysterious messages that suggest their missing friend is watching them. First up: Each girl receives a message about a personal secret she wants no one else to know. Among those secrets: a father's affair; some shoplifting charges; an attraction to a sister's fiancé; and an attraction to a female neighbor.
The circumstances surrounding Alison's disappearance continue to haunt Aria, Emily, Spencer and Hanna, as questions arise about the night she went missing. To complicate matters, Jenna's return to Rosewood makes the girls face an unpleasant past and an incident that sealed their friendship forever. Can the girls face what has taken place in their past, especially since "A" won't let them forget?
Meanwhile temptation is everywhere they look, as Aria tries her hardest to stay away from Ezra and Spencer won't shy away from her sister's fiancé, Wren.
Det. Wilden looks for answers as he uses his connection to Hanna and Ashley to his advantage. Meanwhile, the girls honor Alison; Aria runs into her dad's ex-mistress; Spencer deals with Melissa's vengeance; and Emily sees a new side of Toby.
The girls try to put an end to "A" by blocking unknown users in their e-mails and texts. Meanwhile, various surprises await them, including a gift from a potential love interest, unsolicited advice and unwarranted academic recognition.
The girls deal with the repercussions of ignoring "A" and remain troubled by her lipstick message. Meanwhile, a new boy arrives on the scene; and various romances face challenges, thrive or remain in limbo.
Some ugly secrets cast a shadow on the school's homecoming dance, and one girl's surprising date choice may complicate things for her. The band 2AM Club performs at the dance.
The girls deal with the fallout from the homecoming dance as they mull over a secret about Toby. Meanwhile, Aria starts getting troubling text messages from someone besides "A."
Alison's brother returns to town and thwarts the girls' plans for her memorial service. Meanwhile, Det. Wilden reappears on the scene; and Hanna's home life threatens her social status at school.
The girls are stuck at school when a storm hits town on SAT day, and though the testing is postponed, the girls are still stressed about lingering personal problems. Elsewhere, Byron seeks parenting tips from Ashley as his marriage continues to crumble.
The girls go on an upscale camping trip for a classmate's birthday party, and a text suggests that "A" may be in attendance as well. Meanwhile, the FBI comes to town after new evidence about Alison's case surfaces; and financial strains weigh on Ashley.
Hanna is taken to the hospital in the wake of the hit-and-run, and her friends lean on each other and retrace everything that's happened to them since "A" entered their lives.
Hanna mends in a wheelchair upon her release from the hospital. Meanwhile, Aria and Fitz think someone knows about their relationship; Spencer's romance with Alex hits a snag; and Emily invites Maya to dine with her family.
"A" tempts Hanna to return to her old criminal ways. Meanwhile, Noel continues to go after Ezra; Emily's mother stops pretending to accept Maya; Spencer adjusts to her sister's marriage; and the girls get some surprising assistance.
A wish comes true for one of the girls, but surprising consequences follow.
Emily returns to the swim team and faces competition from a jealous teammate. Elsewhere, Aria and Ezra attempt to go on a date in public; and Spencer confronts an ugly part of her past when she asks Jason for some details about the night Ali died.
Emily wants to swim the coveted anchor leg in a meet, but she has to battle Paige for it. Meanwhile, Hanna must repay Caleb for a favor; and Spencer has ulterior motives when taking on a tutoring job.
Aria's father has a parent-teacher conference with Ezra. Elsewhere, one girl lets down her guard with an untrustworthy person; and a wrongly accused individual finds a friend.
Stress takes its toll on the girls as they scrutinize suspects in Alison's murder, including a classmate with a grudge, a secretive brother-in-law and the ever-mysterious "A." Meanwhile, Aria uses the school play as a way to bond with Ezra.
The police think the girls are fabricating stories when they make claims about Ian. Meanwhile, some clandestine relationships flourish, and others flounder.
Spencer looks increasingly guilty. Meanwhile, the girls realize that other people in town are keeping secrets.
Off. Reynolds keeps a close watch on the girls as Rosewood celebrates Founders' Day. Meanwhile, the girls hide their feelings and the status of certain relationships, such as Hanna's love for the boy who broke her heart and Spencer's friendship with Toby.
In the first-season finale, the girls recruit an unexpected ally to assist them in stopping "A."