Season synopsis
Contains spoilers for this season and earlier seasons.
The season opens with Ian’s body missing, leaving Aria, Spencer, Hanna and Emily publicly discredited and their parents pressing them into therapy with Dr. Anne Sullivan. Their families try to keep them apart, but the girls keep investigating. They eventually find Ian’s body with a supposed suicide note and realize “A” assembled it from earlier messages to frame him. Suspicion falls on Jason, Alison’s brother, and Jenna, whose relationship with police officer Garrett Reynolds makes the girls distrust him.
“A” keeps forcing the girls into public compromises: the messages disrupt Hanna’s father’s wedding, threaten Toby, and push the Liars into a trap involving Dr. Sullivan and a shovel that police connect to Alison’s death. Emily is nearly killed when she is locked in a barn with carbon monoxide, then rescued by someone she believes is Alison. Aria tells her parents about Ezra before “A” can expose them; Byron gets Ezra dismissed from Hollis, so the two continue their relationship in secret. Hanna and Caleb reunite after their earlier split, and Spencer ends her relationship with Toby under pressure, though the separation does not hold.
The friends trace Alison’s clues to the Lost Woods Resort and a masquerade, where Spencer follows a lead with Mona. Mona is revealed as “A”: she says she wanted revenge because Hanna’s friendship with the others took Hanna away from her. She threatens Spencer with a choice between joining her team and disappearing, but the others arrive and Mona falls from a cliff. Mona survives and is committed to Radley; a red-coated visitor appears there, suggesting Mona had a superior. The finale also confirms that Maya has been murdered, leaving Emily with a loss the season does not solve.