[s2e13] The First Secret -

The episode provides critical context for the secrets the girls kept before "A" began harassing them:

" The First Secret " is the of the mystery drama series Pretty Little Liars . Originally aired on October 19, 2011, it serves as a prequel/Halloween special that takes viewers back to the autumn before the show's main events began. Plot Overview [S2E13] The First Secret

Discovers her father, Byron, having an affair with one of his students, Meredith, and is sworn to secrecy. The episode provides critical context for the secrets

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” Fans often cite this as a top-tier episode