[s2e13] The First Secret -

Discovers her father, Byron, having an affair with one of his students, Meredith, and is sworn to secrecy.

"The First Secret" reveals that Alison was being stalked long before the other girls were. Throughout the episode, she receives threatening texts and a package containing a creepy voodoo doll with the message: “It’s my turn to torture you” . This suggests that "A" (later revealed to be Mona Vanderwaal) was already active and targeting Alison months before her disappearance. [S2E13] The First Secret

The girls are desperate for an invite to Noel Kahn’s legendary Halloween party. Discovers her father, Byron, having an affair with

Fans often cite this as a top-tier episode because it fills in essential gaps in the Rosewood lore. It highlights Alison’s manipulative nature and the complex power dynamics she held over her "friends," while also planting early clues about the and the identities of those who hated her most, such as Lucas and Mona. Pretty Little Liars S2.E13 “The First Secret” This suggests that "A" (later revealed to be