The couple first met in the time jump, probably because they worked at the same company. They broke up about a year after starting their relationship because Aria decided to get back with Ezra and end her relationship with Liam.
When The Liars meet again, Hanna asks Aria how’s Liam. Aria says Liam is adorable, but he hates when she says that to people. Later that day, Aria visits her father and hands him a book that Liam wanted Byron to have. Byron asks Aria if Liam is trying to impress him, Aria says he is, and Byron tells him that if she is, he's off to a good start.
When Hanna and Aria are talking about when they told their new partners what happened years ago, Hanna says she did it when she realized she was falling in love with him and Aria replies "Liam and I aren't there yet but I know he's gonna have a lot of questions when I get back". In Boston, Liam knocks on Aria's office window, welcoming her back and she formally greets him. Their boss tells them that there will be a staff meeting in two minutes and, after the other employees walk out, Aria and Liam share a quick kiss and say that they've missed each other. After someone enters the room, they quickly break apart and Liam asks how Ezra is. She says that she only spoke to him briefly, but he's thinking about giving back his advance and Liam says that Jillian isn't going to like that.
Later that day, Aria and Liam speaking to Jillian in her office. Jillian says that Aria told her she had a relationship with this person and Aria says that Ezra was her high school teacher; Jillian finds it hard to believe that he told her he was thinking of giving his advance back, but Aria reminds her of what happened to Nicole and says that he is not in a good place right now. Jillian tells her that no writer is ever in a good place and believes that Ezra is not taking Aria seriously because she was his student, then tells Liam to take over.
After that, Aria and Liam are talking about their meeting with Jillian with a paranoid Aria saying that maybe Jillian knows about them. Liam tells her that she just wants the pages and he'll step in if Ezra isn't taking Aria seriously; she tells him that that isn't the issue, but that he isn't the same person that they met on his book tour. She wants to talk to Jillian and ask for another shot, and Liam jokingly tells her to duck if she picks up the phone. At the end of the episode, Aria is looking at the files on Ezra’s thumb-drive, she gets a call from Liam, but declines it.
Aria is video-chatting Liam telling him about the coverage she has. He sees Pigtunia and jokingly asks if there are posters of Justin Timberlake, and tells her that their boss won't be back until tomorrow. Aria is confused until Liam tells her that their boss is coming back early and that she shouldn't be worrying about the book pages because their boss is kind of over him. Liam tells Aria that Jillian called Ezra, who sounded wasted early in the morning. Aria immediately comes to Ezra's defense saying that he wasn't wasted; he's just dealing with a lot of grief. Liam tells her that he thinks Ezra has a lot more stories to tell.
Later that day, Aria gets another video call from Liam who is taking off his shirt; he tells her that he has to pick up Jillian's mother and take her to a trustee meeting, then jokes that he's a male escort for eighty-year-old cougars. Aria tells him that Hanna and Emily are with her, so he greets them and tells Aria that if Jillian doesn't have anything from Ezra by tomorrow then she'll move on. Aria asks him to tell her that she'll have something on her desk by tomorrow, before ending the call. Back at Aria's house, Aria gets a phone call from Liam; he tells her that Jillian loved the chapters, which surprises Aria. Liam says that she's the book whisperer and that she should keep doing whatever she's doing.
Aria spots Liam and greets him with a warm hug, before pulling back and asking what he's doing there. He asks if that was it for the welcome, causing her to say it wasn't and asks if something is wrong. He says that he wouldn't come all this way for bad news, causing Aria to smile and she officially introduces Emily to him. Emily then says that she'll text Aria when she knows and leaves. Aria then asks him what's up and he says that they need to talk about Ezra Fitz and the book, causing Aria to tense up.
Later that day, Aria and Liam at The Brew discussing their boss; he tells her that Jillian is excited and it'd be good to keep her that way, before asking if Ezra sent her any more pages. She says that he has, causing Liam to ask if he can see them since him being there meant that she wouldn't have to post them online. She agrees to show him the pages and he tells her that their boss had notes about the tone of the pages. She asks what kind of notes.
After that, Aria and Liam looking over the book pages. She asks his opinion and he says that he thinks it's beautiful. Aria asks about the notes her boss left, but he assures her that everything is fine and admits that her former teacher is a terrific writer. He adds that he gets a rush reading Ezra's work in manuscript, the same rush that he gets when he reads her writing. Aria realizes that he knows she wrote a majority of the pages. Liam asks her if Ezra is in Rosewood or maybe a little incapacitated, but Aria says that he isn't. Liam then asks if Ezra knows what she's doing and what she thinks she's doing.
We then see Aria telling Liam that she never intended to start writing the book, but wanted to keep their boss interested. He says that she did that and she asks if Ezra is going to get in trouble. A confused Liam asks why she isn't wondering if she'd get in trouble and she says she took that for granted. He tells her that there is a fine line between trouble and high adventure; he thinks that she should finish the chapter and that they'll figure something out if Ezra doesn't get back soon. She immediately says that Ezra will be back and Liam tells her that he probably will, but she'll have to explain the creative writing she's been doing.
Aria and Liam discussing Ezra; Liam says that she has to tell him, but she asks how she can do that when he spent the last week pounding out chapters. Liam says that if he leaves for Boston before she can tell him, but Aria interrupts saying that he won't because he wants her feedback. He asks if she's slept at all, causing her to say that she'll sleep when she's unemployed and that she's going to get fired. Liam says that their boss loved what she wrote and could offer a book contract, but Aria says that that's because Jillian thought Ezra wrote it. He tells her that she needs to tell Ezra and that hopefully he'll be flattered, have an epiphany and call their boss saying he wants to take the book in another direction. She thinks that the word he's looking for is "betrayed"; Liam says that two weeks ago Ezra was pouring rum over his corn flakes, so he's lucky that someone who sat in the back of his classroom cares enough to save his reputation. She tells him that it's not that simple and that she'll tell him that afternoon.
Ezra at The Radley where Liam introduces himself; Ezra asks what he's doing in Rosewood, causing Liam to say that Aria invited him to her parents' wedding. Ezra says that he's meeting with Aria to discuss the book, which Liam says he is looking forward to reading. Ezra says that he just wants to make it clear that the protagonist was inspired by a woman he traveled the world with, it's not Aria. He says that they never left Philly and jokes that some can find romance at the Liberty Bell, causing Liam to realize that they were romantically involved. Aria walks over and greets them before asking how long they were waiting. Liam says that it wasn't long, but says he'll leave them so "Mr. Fitz" can get his feedback. Aria follows Liam asking if Ezra knows about her ghost writing, but he says that now he knows that Ezra was more than just her favorite teacher and asks if he's why she wanted to stay in Rosewood. Before she can answer, Liam steps into an elevator and Aria is standing alone.
After Aria performed the ceremony, she spots Liam. He asks Aria where her parents are going for their honeymoon and she says that her mom had a groupon so they're going to Atlantic City. She then says that she's joking and they'll be at a motel down the shore where they spent a college weekend, which Liam says is sweet. She thanks him for coming and he says that he's glad he did: it was helpful to hear her thoughts about true love and commitment. She apologizes for not being honest about her history with Ezra, causing him to ask why she held back. She says that she wasn't being completely honest with herself and it was complicated. He says it wasn't if she was writing about him on the page, but she says she wasn't but then says maybe she was. She says that she's confused, but maybe writing about it helped her figure things out. Liam cautiously asks if she has and she said she thinks so. He asks how it ends and she says she didn't know until right now; they smile at each other and share a kiss.
In Aria's house, Aria and Liam kissing on the couch, as a figure moves around outside casting shadows. There is a knock on the door and Aria is surprised to find an elated Alison and Elliott; Ali apologizes saying that she told Elliott it was late and they were sleeping, but he says they weren't and points Liam out.
Aria and Liam are having lunch at Radley; she tells him she didn't have to do all of this, causing him to say that that's what an expense account is for: taking his girlfriend out for an omelet and billing it as lunch with a client. She says that that might not be as big of a lie as he thinks; she tells him that Ezra called Jillian wanting to get her off the hook and asked her to be his co-author. She adds that she had no idea he was going to do that and neither did Ezra, causing Liam to say that Ezra made a decision. He then apologizes and says that he's really happy for her.
When Aria is at the hospital, Liam opens the door and is glad to see that Aria is okay, then thanks Ezra for being there. He also brings good news: Jillian approved the book. He congratulates Aria on becoming an author and kisses her, as Ezra slips out.
Aria cheats on Liam with Ezra.
While Aria is at a bar, Liam rings her but she declines.
Aria receives a text from Liam saying "Sleepless nights and big news. Be there soon!" She reads this, then places her phone back on the table. Later on, at Aria's house, Liam is sitting on the sofa and Aria is standing infront of him. She is telling him how they both saw this coming. Liam then says "One of us saw it before the other". Aria apologies. Aria then begins to open up about this situation about her coming home, seeing her friends, the Ali situation. She also realises she has a lot of unresolved things, adding that it wouldn't be fair to him. Liam thinks Aria is wanting himself to thank her but he doesn't want to, but Aria just wants him to understand. In addition, she states that it is not about the book or Ezra. When Liam hears Ezra's name he looks up at Aria. She then says it is just her. Liam questions her about it being just them two, with Aria replying "Yes", She apologises once again and attempts to hold Liam's hand but is stopped because he stands up and tells her not to say it anymore. After a pause, he then tells Aria that he has a surprise for her too. He tells Aria he is back on the book. Editing and a "Creative gatekeeper". He also has a duty to make everybody reasonably happy. He asks Aria if she has a problem, which Aria replies that she doesn't know. Liam then sits back down praising that she had worked hard for this and Liam wants to see Aria get something she has always wanted. After another pause Aria says she is almost there. Liam replies "Yeah... almost". Aria says that they will do it and make it work. Prompting Liam to want to cross the finish line together.
Liam is in the car watching Aria and Ezra on the bench. He also spies that Ezra puts his hands with Aria's. Liam gets out the car still looking at the both of them. He shuts his car door before walking away. The scene jumps to when Liam and Ezra are working on the book. He notices a problem with Ezra's backstory, Ezra queries it but Liam shuts him down by saying the nature of his actions. Ezra asks if Liam thinks the character is predatory, to which Liam agrees. He then talks about the older man and the young girl which makes Ezra uncomfortable. They start to bicker but Ezra then asks if they are looking at the same pages of the drafted book. He explains that they are not that far apart in age. In the intense conversation, Liam says that the character in the book is his 'hero'. Ezra then says that they all want the best book, to which Liam agrees. Liam also points out that there is friction between Ezra's and Aria's chapters in the book. Liam takes it to the next level by saying "Neither one of us want Aria to look foolish, right?" Ezra asks if he means book Aria. Liam then mentions he wants to protect the book which also meaning protecting both authors. Ezra asks what he is protecting them from and Liam says "loss of perspective" and "poor judgement" and "avoidable bad choices". Ezra says he can see that.
Aria is at her house talking to Liam about how he said they could all work together. Liam responds "I meant it when I said it". Aria asks what happens and Liam explains his 'way of words'. He used to admire it but he doesn't anymore, he is suspicious. Aria demands why he doesn't admire it anymore. Liam says it's a lot of unconnected things that he doesn't want to connect anymore. He says that Aria and Ezra's history, what they both have been writing, how they have been writing it and what changes in a room when they are alone together when somebody else walks in, all clicked together. Aria stops him before he can say anymore and asks "What do all these connections mean?". Liam thinks Aria was suduced by her English teacher, Ezra, when she was in Highschool. Aria pauses to try and think what to say next. She then says "That is not how it happened". Liam looks upset and walks behind her. Aria turns around and says there is no possible way for her to explain this to him. Liam wants her to try and explain it to herself. Aria talks about the button that she could push to make all the complicated things in her life not to happen. She carries on explaining about if she had pushed it, all the people who have died would still be alive, she wouldn't of hurt anyone or disappoint them and nobody would of hurt or lied to her. But Aria then says if she pushed the button, she would of be gone to. She describes that she is herself because of what has happened to her, what she has done and who she has loved. Aria explains that she likes herself because of it.
Aria reveals that Liam went back to Boston.