<P> After Ian Thomas is pushed down by "A" from the top of a bell tower and his body goes missing, the girls are forced to keep their friendship a secret and to maintain therapy sessions with Dr. Anne Sullivan to discuss about Alison's absence in their lives, a fact that their parents believe to be the reason why the girls are behaving strangely . Days after, through Spencer's sister Melissa Hastings, the girls find Thomas' dead body, accompanied by a suicide letter in which he admits that he killed Alison . Following, the girls continue to be threatened by "A ." Garrett Reynolds is arrested for Alison's murder after Jenna Marshall hands the Rosewood Police Department a missing page of Alison's autopsy . The second season ends when Mona Vanderwaal--a Rosewood High student and one of Alison's victims of bullying when she was alive--is revealed as "A ." </P> <P> The third season is set five months after the previous one . One night, Spencer, Hanna, Emily and Aria get together in Spencer's living room to drink and enjoy a life without a stalker . Emily, however, is still mourning over the death of her ex-girlfriend Maya St. Germain, who died in the same night of Mona's reveal . After drinking more than expected, the girls wake up in the midst of night to discover that Emily has disappeared . They later find her in the cemetery, standing on Alison's graveyard, with Alison's body gone . With Emily drugged and they involved in a crime, the girls then promise to keep the secret . They dispose of all evidence connecting them to the happening, including all of Emily's clothes . A new person using the "A" identity soon restarts the stalking game . The new stalker threatens them with what happened previously . Mostly of the season's episodes revolve around the question of where Alison's remains are . The girls later on befriend new resident CeCe Drake, a woman physically and psychologically similar to Alison . Drake reveals to them that she and Alison were best friends when Alison was alive, years prior . Throughout the following episodes Drake gets intimate with the girls, who are suspicious of her Alison - like behavior . Later on, Alison is shown in more flashbacks of the night she disappeared, with some revealing that Alison met with CeCe, Aria's father, Jenna Marshall and Garrett Reynolds that night . In sequence, the girls discover, in Alison's biology notebook, a conversation between her and a friend in which Alison talks about a "beach hottie ." The girls investigate while a figure using a red coat starts to appear periodically to them, and they begin to believe that it is Alison . In the meantime, Mona and Spencer's boyfriend Toby Cavanaugh are revealed as helpers (and double agents) of the new "A ." With the help of the two, the girls plot a trap to catch "A," but the stalker uses their own setting against them, and, during a fire, the girls are saved by Red Coat . Hanna wakes up and sees Red Coat staring at her, and the person is revealed to be Alison . Afterwards, Mona and Spencer claim that they also saw Alison . On the way back to Rosewood, Mona reveals that Red Coat would sometimes wear a mask that looked like Alison's face, meaning that Red Coat could have just looked like Alison . </P> <P> After the girls find Alison's diary, they try to understand her . Throughout the season, Alison is shown in several flashbacks concerning her behavior, mostly based on histories written on her diary . The girls later meet Carla Grunwald, who tells them that she helped Alison step out of the grave that she was buried; Grunwald then drove her to a hospital, but Alison ran away . With this confirmation, the girls start a quest to find Alison, following the steps of two persons using the Red Coat costume, one of them being revealed to be CeCe . Fortunately, after a Halloween party, the girls follow a Red Coat, who is revealed to be Alison . She tells the girls that she needs their help, but she vanishes shortly after . Alison later appears to Emily and starts requesting things to her . The season ends when Alison sits down with her friends to explain everything that had happened to her two years earlier . </P> <Table> <Tr> <Td> </Td> <Td> This section is empty . You can help by adding to it . (March 2018) </Td> </Tr> </Table>

What season does alison return in pretty little liars
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