Mary Drake

Casting

Andrea Parker had portrayed Jessica DiLaurentis since the second season, thus placing her as the actor behind Mary Drake, as Mary is Jessica's identical twin. TVLine confirmed that Parker was added as a series regular for the seventh season.

Background

Mary's mental health issues allegedly began to show up when she was a teenager, after an incident took place at her sister's job. Jessica was babysitting Teddy Carver, when she phoned Mary to come and replace her. While babysitting, the baby died under Mary's care and she was sent to Radley Sanitarium. Mary told the baby's parents she hadn't even touched the boy and that it was her sister's fault, but no one believed her word due to Jessica manipulating people into thinking she was volatile. Mary was forced to stay in Radley until she was 18. However, the woman was readmitted several times over the following decade and eventually gave birth to Charles inside the asylum. The baby was then adopted by Jessica and Kenneth since they feared for the newborn's safety. Several years later while still in Radley, Mary gave birth to a second child (Spencer Hastings) that was also taken from her. Drake was permanently released from the psychiatric hospital when she was 28 years old. Not much is known about her whereabouts after checking out of Radley, only that she'd travelled a lot, especially around Europe and Latin America. After discovering that her firstborn had been murdered, Mary returned to Rosewood and began working with Elliott Rollins to avenge her homicide. She is also possibly working with Uber A.

Season 6

Drake's first known appearance in the series took place in "Did You Miss Me?". She dressed up as Jessica, in order to visit her niece Alison DiLaurentis in the local town's hospital. Alison assumes she's having a dream due to the state of her concussion. Mary proceededs to tell Alison that she's happy with her niece's marriage to Elliott Rollins and that he'll be able to protect her in a way that she couldn't.

Throughout "Hush, Hush, Sweet Liars", Mary and Elliott dress up as Jessica DiLaurentis and detective Darren Wilden in order to drive Alison insane and trick her into checking herself at the Welby State Psychiatric Hospital. Footage of Mary nearby the fence Caleb built outside the Lost Woods Resort is later captured. However, the Liars were unaware of Drake's existence and mistook her for Jessica instead. As they left the forest, Mary returned to the DiLaurentis' house where she met Elliott. There, she asks if Alison "signed the papers." Elliott confirms, stating that 51% of the Carissimi Group shares were diverted at the time Alison signed her entry to the psychiatric hospital. Drake reveals that she is planning a revenge against her deceased sister. She then tenderly glances at a picture of Charlotte in a frame and states that her daughter would've approved her schemes.

Season 7

In "Tick-Tock, Bitches", the Liars, Mona, Toby, Ezra and Caleb witness Mary walking towards the police station, while they're trying to come up with a plan regarding Hanna's abduction. After Toby heads there to interogate her, he finds out that Mary is Jessica's identical twin sister and was there to report a break-in at the Lost Woods Resort, her newest acquisition. Deducing she's A.D., they begin spying on her and investigate the motel, only to find out Mary had bought everything it's needed to cover up a murder. Later, Mary visits the Hastings residence and is invited by Spencer inside, for a cup of tea. As she subtly interrogates Mary, Spencer finds out that Drake knows her family suspiciously well. Spencer asks why her existence should be considered a secret, a question by which Mary feels offended. She apologises immediately after, telling Spencer that she can be rather overly sensitive at times. Before she leaves, Mary questions Spencer on knowing about her stay at Lost Woods Resort but she quickly comes up with a credible lie. Whilst driving her car late at night, Mary encounters an abused Hanna Marin over the road and stops the vehicle. Both exchange looks, with Marin gazing at Drake in mass hysteria due to looking like a spitting image of Jessica.

In "Bedlam", Mary drives Hanna to Spencer's home, at her request. Later that day, she visits Spencer again at her workplace to find out if Hanna is doing alright. After some questions posed by Spencer, Drake tells her the story of how she ended up in Radley, resulting in an unexpected bond between the two of them. Visiting The Radley to unlock old memories, Mary encounters Emily and they discuss Alison's health issues. Drake assures Emily that Elliott is professional and thinks there is nothing to worry about. They decide to pay Alison a secret visit at Welby. There, both of them discover that Alison's mental state has worsened since she mistakes Mary for her deceased mother. After Elliott discovers their presence, he argues with Mary about their plans, as she thinks Elliott is crossing the line on Alison's mistreatment.

At the end of "Hit and Run, Run, Run", Mary pays another visit to Alison at Welby to inform her that she's "in charge" of things.

In "Along Comes Mary", Alison is released from Welby into the care of a relative, leaving her under the suspicious watch of Mary. Their interactions are initially tense since Alison questions her aunt's intentions and sudden return to Rosewood. Mary discloses to Alison that Archer Dunhill (Elliott's real identity) contacted her in London to inform that Charlotte had died just hours after her release from medical supervision. Archer also acknowledged his suspicions that Alison was accountable for her cousin's homicide. Mary admits that at first she too believed Alison was responsible for her daughter's murder, presuming she had inherited Jessica's ruthless nature but claims she stopped assisting Dunhill's schemes once he revealed his true colors. Later on the episode, the two bond over "Little Sparrow", a song Mary was heard humming around the DiLaurentis residence about betrayal and heartbreak, which coincides with Alison's current situation.

In "Wanted: Dead or Alive", Mary moves back to the Lost Woods Resort in fear of Archer potentially lurking around town and nearly bashes Spencer with a bat when she opens the door to her room unannounced. Drake realizes that Spencer suspects her of keeping Archer concealed and proceeds to tell her that he "handled Ali with kid gloves" compared to how he treated her. Later, when Mary drops by the DiLaurentis residence to return some items, Alison questions her aunt's relationship with Charlotte due to her cousin introducing herself with the pseudonym CeCe Drake. Mary is in shock to find out about her daughter's former alias, claiming they never met and that once Charlotte was born, Jessica immediately took the baby, not even allowing her sister to hold the newborn. Mary presumes that Charlotte discovered about her existence either on her own or through Jessica.

During "Original G'A'ngsters", Spencer and Hanna manage to break into Jenna Marshall's room at The Radley with Caleb's aid, but their investigation process is quickly interrupted by the sound of someone slowly opening the door. The person hides Mary's old Radley Sanitarium file inside a secret box under Jenna's bed and is revealed to be Noel Kahn, who is seen angrily dialing Dr. Cochran. Meanwhile, Jason DiLaurentis returns to Rosewood and tensions rise at the DiLaurentis residence when he corners Mary with a court order appointing him as Alison's primary caretaker. He initially expels Drake from the property but Alison manages to subdue her brother into getting to know their aunt. During an awkward family dinner with Aria Montgomery, Jason accuses Mary of being a master manipulator and she confesses to them that Jessica had told her Charles died as a teenager in order to withheld information about her son's transition into a woman. Drake also claims that her sister spent a lot of time locked in a storm cellar at their Aunt Carol's house. Later at night, the Liars but Aria go to investigate the location, and discover Jessica had turned it into her lair. Through photos, Alison realizes her mother knew she was alive and searched for her whereabouts. Jessica also kept files on all the Liars and had all of Mary's medical history. Whilst examining them, Emily discovers that Mary had a second child, Charlotte's biological sibling. Their gender is undisclosed, but the individual fits the same age pattern as the Liars.

In "Exes and OMGs", Spencer and Aria track down Dr. Cochran and meet his daughter whom he has a strained relationship with. She refuses to tell them where he lives until someone ransacks her home. Upon meeting Cochran, he is reluctant to discuss his past until the girls bribe him with whiskey. The man explains that his main function was to take care of "problems" such as unwanted pregnancies. He further admits that he was responsible for delivering both of Mary's children when she was hospitalized at Radley. Cochran also proceeds to reveal that her second child was placed in temporary custody at a department of county family services. Years passed and his job eventually caused him to be a liability, so Radley fired him and he lost his license as a doctor.

During "The Wrath of Kahn", Aria and Jason team up to investigate Mary's past and discover that Steven Kahn, Noel's father, was the judge who presided over her second child's adoption.

In "The Darkest Knight", Hanna Marin helds Noel hostage in an attempt to obtain a confession from him that proves he's their tormentor, but Kahn doesn't regain consciousness. Impatient, she instead ends up slashing his legs with a knife in order to test his DNA and see if it matches Mary's. The results later come back negative and Noel ends up escaping. The Liars all get a text message ordering them to head over to 1465, Elm Street. Once the girls arrive to the location, they make their way inside an abandoned school for blind students where they're held hostage by Kahn and Jenna, with the later tracking down the Liars at gunpoint. During the cat-and-mouse chase, Emily and Hanna end up fighting Noel which causes him to trip over an axe that decapitates him. Spencer is subsequently shot by an unknown assailant, giving Jenna the leverage to finish her off. Nonetheless, Mary emerges from behind and knocks out Jenna before she could do anything harmful. As the Liars meet up with Spencer, they stumble upon Spencer laying on Mary's arms. Presuming Drake is accountable for their friend's critical condition, Mary swears she'd never harm Spencer and tearfully claims to be her biological mother.