Pretty Little Liars [OV]

In the series premiere, four 16-year-old girls believe their secrets are safe forever after their friend mysteriously vanishes. But the truth may be only one text away.

With the return of Jenna Cavanaugh (recurring guest star TAMMIN SURSOK) to Rosewood, the girls must face an unpleasant past as questions arise about Alison's death.

Old and new relationships are examined as the girls try to pay tribute to Alison's memory. But with "A" taunting them every step of the way, can the girls leave the past behind?

The girls take matters into their own hands and try to put a stop to "A," but the girls' problems are far from over.

Trying to ignore "A" backfired for the girls and now they must pay the penalty. Meanwhile, the girls must also deal with typical teenage drama -- the boy kind.

The homecoming dance is supposed to be a time for fun and making memories, but for four pretty little liars, disturbing secrets threaten to ruin their perfect night.

After the homecoming dance, the girls try to sort out the devastation. Plus, "A" isn't the only one sending Aria texts. Author SARA SHEPARD (Pretty Little Liars) makes a cameo.

Last-minute preparations for Alison's memorial get derailed when her brother, Jason DiLaurentis Jason DiLaurentis (guest star PARKER BAGLEY), arrives back in Rosewood.

The girls are trapped at school as a bad storm brews, and tensions run high. Plus, Byron leans on Ashley for advice on parenting as his relationship with Ella takes a bad turn.

The girls go "glamping" as A's threats escalate and the FBI arrives in Rosewood. But not even a mani/pedi can lift the girls' spirits when the evening takes a dangerous turn.

Moments after Hanna is hit by a car, the girls' world is turned upside down. Meanwhile, the mysterious messages from "A" continue.

As the girls try their best to support Hanna as she returns from the hospital, everyone has their own "surprises" to deal with. Plus, Aria and Ezra suspect someone is on to them.

Aria and Ezra feel as if there may be no way out, Emily deals with opposition to her love life and "A" has Hanna jumping through old hoops. The girls get a little unexpected help.

The school dance-a-thon might give the girls more than sore feet. Plus, Aria's old babysitter, Simone (ALONA TAL - Supernatural), comes to visit, and sets her sights on Ezra.

Emily deals with a jealous teammate (LINDSEY SHAW). Aria and Ezra plan their first date out in the open. Spencer turns to Ali's brother, Jason (PARKER BAGLEY), for information.

At a crucial swim meet for the Rosewood Sharks, Emily and Paige (LINDSEY SHAW) are pitted against each other. Plus, Caleb (TYLER BLACKBURN) calls in his favor with a guilty Hanna.

It's parent-teacher conferences and one little liar's father sits face to face with the love of her life. Better believe that "A" has something to say about it.

As tensions rise, the girls ponder the true nature of evil. Plus, Aria views the school play as an opportunity to get closer to Ezra, but will her plan backfire?

After a shocking revelation from the police, it looks like the four little liars could be crying wolf. With everything pointing to Ian (RYAN MERRIMAN), could the girls be wrong?

As the heat is turned up on suspicions surrounding Spencer, the girls must come to the harsh realization that they aren't the only ones hiding secrets in Rosewood.

Everyone has something to hide. For Aria, Emily, Hanna and Spencer, keeping things hidden is second nature, but having to live with those secrets can become a big burden.

In the season one finale, the girls go to an unlikely source for help to put an end to "A" and the mystery surrounding their friend. Can they really stop "A" once and for all?