In the episode, the main characters Aria Montgomery, Spencer Hastings, Hanna Marin and Emily Fields find themselves apprehensive one year after the disappearance of Alison DiLaurentis.
Alison's body is then found in her former home, and after the funeral, the girls receive a frightening anonymous message signed by "A".
Aria and her parents traveled for a year to Iceland; Hanna Marin underwent a complete style transformation, becoming the it-girl of Rosewood's social scene, and is friends with Mona Vanderwaal, who used to be bullied by Alison; Emily Fields focused on her swimming skills, hiding that she is attracted to girls and was in love with Alison; and Spencer focused on her studies and struggled to become Rosewood High's number one student.
The Montgomerys return to Rosewood after spending a year in Iceland, and Aria finds herself unable to adapt again to the town's mediocrity.
Spencer receives a message from 'A' which makes her remember she kissed Ian Thomas, Melissa's former boyfriend, in the past.
And I know everything -A.. "Pilot" was written by the series' showrunner and main collaborator, I. Marlene King, and directed by Lesli Linka Glatter.
[2] The opening theme song for Pretty Little Liars is "Secret" by The Pierces, which was suggested by one of the show's stars, Ashley Benson.
[4] Lucy Hale was cast as Aria Montgomery in the project, followed by Troian Bellisario as Spencer Hastings and Ian Harding as Ezra Fitz in November 2009.
[7] The Alloy Entertainment website later confirmed that Pieterse would be playing Alison DiLaurentis and DeVitto would be Melissa Hastings, also mentioning the casting of Janel Parrish as Mona Vanderwaal.
[12] The actors who played Ian Thomas, Toby Cavanaugh and Jessica DiLaurentis in this episode were after replaced by Ryan Merriman, Keegan Allen and Andrea Parker, respectively.
[18] The New York Daily News gave the show a positive review, commenting that it "makes most popular vampire romances look anemic", while concluding, "Pretty Little Liars could go in several directions, including mundane teen clichés.
"[20] The New York Post gave the show three out of five stars, stating, "OK, so we've established that there is no socially redeeming value in this series and that your kids shouldn't watch it if they are too young and impressionable.
"[21] The Los Angeles Times wrote that the series is "one of those shows that manages to mildly, and perhaps unintentionally, spoof its genre while fully participating in it, and that's not a bad thing at all.