Pretty Little Liars, Monsters in the End

When their best friend mysteriously vanishes, four girls believe their secrets are safe forever. But when they begin to receive threatening messages, the truth may be only one text away.

After receiving a series of increasingly disturbing texts, Imogen and her newly-formed friend group -- Tabby, Faran, Noa and Mouse -- plot to end Karen's reign of terror. Later, Karen and her twin sister Kelly hatch a payback plan of their own.

'The past will come back to haunt you' -- this saying has never been more true than for Aria, Spencer, Hanna and Emily. As the girls try to pay tribute to Alison's memory, the four friends are faced with unresolved issues.

Tired of being harassed by 'A,' the girls decide to put a stop to the emails and text messages by blocking all unknown users. But just because the mysterious ghost isn't looming over their heads, the girls' problems are far from over.

Trying to ignore 'A' backfired for the girls and now they must pay the penalty. Whether it is a family in crisis, parental praise for an undeserved honour or wearing scrubs while working off a debt -- the girls must deal with it all.

The Homecoming committee is knee-deep in balloons and girls are jockeying to be queen, while four friends try to stay afloat. Will the girls be able to protect one of their own or will the evening turn into a night they can never forget?

In the aftermath of the disastrous homecoming dance, the girls try to sort out the devastation. Parents, boyfriends, siblings and friends are all in flux, and if the little liars don't act fast, the situation could go from bad to worse.

The day of Alison's memorial is around the corner and the girls are ready to say their good-byes. But when Alison's brother Jason arrives, Spencer, Aria, Hanna and Emily quickly learn that saying good-bye is at the bottom of his list.

A day of SAT testing is put on hold when a violent storm hits Rosewood. But instead of being able to enjoy the postponement of academics, the girls are stuck inside the school dealing with the drama that follows them everywhere.

The discovery of a new piece of evidence about Alison's disappearance brings the FBI to town, and the last thing the girls want to do is go 'glamping' (glam-style camping) for a birthday party.

The mystery and ominous messages continue for best friends Emily Fields, Spencer Hastings, Hanna Marin and Aria Montgomery. No longer just threatening to reveal secrets, the all-knowing 'A' has stepped up the game and nothing is off limits.

Hanna's return home from the hospital should be a joyous event, but being stuck in a wheelchair and feeling haunted by 'A' makes her return feel more like a Hitchcock nightmare than a proper homecoming.

Relationships are in flux in Rosewood as the girls face obstacles. With the support of each other, however, and unexpected help from an unlikely source, the future for the girls doesn't look so hopeless.

As the school gets ready for the dance-a-thon, Aria, Emily, Hanna and Spencer have more on their minds than just raising money for the school trip to Washington, D.C.

The girls try to resume a sense of normalcy, but even the simple tasks of dating and extracurricular activities meet with strife. Emily must deal with a jealous teammate, as Aria and Ezra plan their first date out in the open.

A crucial swim meet for the Rosewood Sharks is the setting where Aria, Emily, Hanna and Spencer experience a lot of turmoil. As secrets start to be revealed and antagonists become less threatening, could the game be changing for the girls?

What happens to one little liar when parent-teacher conferences come around and her father sits face to face with the love of her life? What about when another one reaches out to a tarnished innocent, when nobody else will?

As their doubts, fears and suspicions grow, Aria, Emily, Hanna and Spencer start to wonder what the true face of evil looks like. Only time will tell who the bad seed is.

After a shocking revelation from the police, the spotlight is turned on four little liars who look to be crying wolf. But with everything pointing to Ian, how could the girls be wrong?

Everyone has a secret in Rosewood and it's only a matter of time before it is revealed. Four girls know this to be especially true and are reminded of it on a daily basis.

Rosewood's Founders Festival sets the stage for more secrets. Everyone has something to hide -whether it is a romance, or revealing a true identity and intentions. For Aria, Emily, Hanna and Spencer, keeping things hidden is second nature.

In the season one finale, now that Aria, Emily, Hanna and Spencer are in possession of the information that Alison left them, the girls decide that it's time to finally put an end to 'A' and the mystery surrounding their friend.