Alison DiLaurentis (Book Character)

Alison Lauren DiLaurentis was the most popular girl at her middle school Rosewood Day.

Physical Appearance
Alison has long, wavy blonde hair, large deep blue eyes, a small button nose, and a heart-shaped face. She is/was considered to be the prettiest girl at Rosewood Day.

Biography
Alison DiLaurentis was the most popular girl at Rosewood Day middle school. Unfortunately, she never got to have the full middle school experience as her insane twin sister Courtney fooled their parents into taking Ali to the mental institute instead of her. In revenge, she killed Courtney three years later and attempted to get revenge on her sister's friends as well. She was the second "A".

When she first arrives in Rosewood Day in third grade, Alison holds commanding reign over the school, with every girl wanting to be her and every guy wanting to date her. During a Friday afternoon in sixth grade, Ali spots a flyer for the Time Capsule Tradition, and boasts that she will have a piece flag given to her by her brother Jason. That weekend, Courtney was home from the Radley, her old mental institute that was being turned into a hotel, in order to switch to a new clinic, the Preserve at Addison-Stevens. Sometime that Friday, Ali's signature 'A for Ali' ring was stolen by her twin. On Saturday morning - the day Courtney was to be taken to the Preserve - Hanna, Aria, Spencer and Emily each arrive at the DiLaurentis home to steal Ali's flag piece. However, Courtney spots them shortly after arguing with Ali and immediately comes out and pretends to be her sister.

Courtney successfully tricks her mother into taking Ali to the Preserve. Ali is shocked and insists that she's not Courtney; however, without her ring and with Courtney outside chatting it up with four nobodies from school, she's fighting a losing war. Furious, Ali realizes the only way out is to pretend that she is Courtney.

Two years later, her parents bring her home for the summer, believing that she is improving and are considering a slow transition to letting her stay home for good. Meanwhile, Courtney has befriended the girls who Ali thinks are the 'un-cool' people of Rosewood Day - Hanna, Aria, Spencer and Emily, and taken over Ali's life completely. While they are having a sleepover with 'Ali' in Spencer's barn Ali spies on them, taking pictures with a polaroid camera. She later buried several of the photos in the vast woods bordering her family's Victorian mansion and Spencer's estate.

When Courtney runs into the woods after an argument with Spencer, Ali confronts Courtney and eventually kills her by shoving her into a hole where a gazebo was about to be constructed in their backyard. Ali, who probably thinks she can get her life back now, is promptly sent back to the Preserve as the media stakes out the DiLaurentis mansion and jumps on the story of a beautiful rich girl who is "missing." Whilst in the mental hospital, Alison befriends a girl called Iris.

Eventually Alison takes over from Mona Vanderwaal and becomes the second "A" so she can continue to stalk the Pretty Little Liars and have her vengeance. Unfortunately, Ian Thomas, who is the prime suspect in Courtney's death, has been conducting his own little investigation and has discovered her family's biggest secret: her twin sister and her insanity. He also seems to be figuring out who exactly he saw arguing with "Ali" in the woods on the night of her murder, and so she kills Ian to keep her secrets safe. Alison later attempts to kill the girls by setting the woods near Spencer's estate on fire. However, Alison is trapped by a fallen branch and is nearly killed as well. Aria finds her and rescues her, and the rest of the Pretty Little Liars see her, but Alison runs away before anyone else can see her, leaving the public to think the girls are hallucinating or possibly even lying for attention. Alison later kills her neighbor Jenna Cavanaugh in the book Heartless because Jenna is one of the few people who know the secret that the DiLaurentis family has a third child. She worries that Jenna also suspected the possibility of the first switch instigated by her dead sister. She pins Jenna's death as well as her sister's on a pervy construction worker who used to work on the DiLaurentis gazebo project years ago.

Alison returns in Wanted, when her parents, who still think she is Courtney, introduce her to the rest of Rosewood, saying that she was 'Alison's' twin, and they didn't want her caught up in the media attention following 'Alison's' death. Alison convinces the rest of the Pretty Little Liars' that she is actually the best friend they knew, claiming that her twin Courtney must have snuck out the house and was killed by the construction worker, causing a mix up with their identities. They all eventually believe her and are thrilled to have their best friend back; of course they have to keep pretending they only know her as Courtney. However, Aria maintains a bit of wariness around Ali, and Spencer inadvertently notes that her sister Melissa has warned her to staty away from "Courtney". Dismayed by this information, Ali keeps a close eye on Melissa and soon realizes she has figured out the truth. She kidnaps and drugs Melissa before she could get to the police.

Alison invites them to a holiday home in the Poconos they had always used to visit with Courtney after the school's Valentines dance. Alison cajoles them into re-enacting the hypnotizing session during the sleepover and they reluctantly agree. Alison planned the night so she could set fire to the house, killing the Pretty Little Liars and finishing what she started with Courtney. Only again, she fails and the Pretty Little Liars escape the house. The house eventually explodes from the fire and it goes up in flames, leaving the girls to believe Ali is still inside and certainly dead. Emily is painfully aware that she left the door of the structure open, leaving the possibility for Ali to escape.