Pretty Little Liars [OV]

Featuring the voice from the all-seeing Mona, this special will go over the Liars history with "A" from the very first text message, to the most recent spotting of Red Coat.

In the season four premiere, the girls turn to Mona for answers, now that she is also being targeted by "A." Plus, the contents of the trunk are revealed.

The presence of Mrs. DiLaurentis (ANDREA PARKER) continues to unnerve all those around her. Toby (KEEGAN ALLEN) shares a heartbreaking secret with Spencer. "A" nearly kills Mona.

Hanna worries her mother is keeping a dangerous secret, which leads to an uncomfortable meeting with Detective Holbrook (SEAN FARIS). Melissa (TORREY DeVITTO) returns to Rosewood.

A new detective means new questions, and the Liars are asked some hard questions. Plus, Spencer lays a trap for Melissa (TORREY DeVITTO). ROMA MAFFIA (Nip/Tuck) guest stars.

Spencer and Emily visit a nearby college, but they have different agendas for their time on campus. Hanna is frantic after another horrifying discovery among her mom's things.

Trying to protect her mom gets Hanna in trouble with the cops. Searching for the recipient of Ali's mysterious phone number leads Spencer and Toby (KEEGAN ALLEN) to Ravenswood.

Caleb and Toby (KEEGAN ALLEN) team up to investigate "A" and what happened the night of the lodge fire. Ezra struggles with how he fits into Aria's life. Hanna tries to act normal.

Caleb tries to convince Hanna that Mona can't be trusted, causing Mona to prove her loyalty in the most unexpected way. Emily reconnects with her old boss Zoe (RUMER WILLIS).

Paige (LINDSEY SHAW) throws Emily a surprise birthday party. Mona's selfless act provides Hanna and her mother with their first bit of good news. Ezra gets some distressing news.

Mrs. DiLaurentis (ANDREA PARKER) offers to let Emily move into Ali's old room. Trying to get involved in Jake's (RYAN GUZMAN) interests, Aria finds an opportunity to follow a lead.

Ezra reaches out to Aria, just as she decides to move on with Jake (RYAN GUZMAN). A Western-themed dance turns into a two-step with "A." Hanna is stalked by a fellow student.

In the summer finale, an intriguing riddle from "A" has the Liars hitting the road and heading to Ravenswood, where they make a shocking discovery.

In the special Halloween episode, the girls crash the Ravenswood Founders Day Celebration after a clue suggests Ali may be alive. Caleb meets a kindred soul (NICOLE GALE ANDERSON).

As the Liars go looking for answers about Alison and try to make sense of their lives for the past year, a darker side of Ezra emerges.

After Hanna shares that she has Ali's diary, the girls hope it can answer some questions. But will Aria, Emily, Hanna and Spencer really admit which personal story is about them?

Shana (AERIEL MIRANDA) says that Ali wants to meet Emily -- and not the other girls -- but could it all be part of an "A" plan? Aria and Hanna deal with matters of the heart.

"A" goes after Hanna in an unexpected way. Spencer works overtime to decipher the stories in Ali's diary. Aria is upset with the new friend Mike (CODY ALLEN CHRISTIAN) has made.

Spencer's hunt for the truth takes a dangerous turn. Will Hanna be able to figure out Spencer's secret? Emily looks to make amends with Alison through Shana (AERIEL MIRANDA).

This special black-and-white episode gives a nod to 1940s-era film noir as Spencer's numerous sleepless nights start to take a toll on her and she heads down a dark and stormy path.

Spencer is determined to tell Aria about Ezra, but Ezra questions Spencer's credibility in lieu of her recent addiction problems. Can the girls trust Spencer?

Aria grapples with Ezra's betrayal while Spencer must deal with the fallout from her addiction. Meanwhile, Paige (LINDSEY SHAW) is fed up with Emily's secrets.

Emily takes up the sleuthing reins and hunts for answers about Ezra and Mona. Hanna begins a new search after being confronted by Holbrook (SEAN FARIS) and Tanner (ROMA MAFFIA).

With the girls still reeling from their own issues, they pull it together to be in a charity bridal fashion show, hoping to get answers from Mrs. DiLaurentis (ANDREA PARKER).

Aria, Emily, Hanna and Spencer finally get answers about the night Ali disappeared. With their newfound knowledge of Ali's long-held secrets, can they figure out who "A" is?