"'Just by walking in a room, she lights it up. Everyone wants to be her best friend, wants to marry her, or both.'" -John Smith, The Rise of Nine
Sarah Hart was one of the main protagonists in The Lorien Legacies series. She was Number Four's girlfriend, and an ally to the Garde. She was portrayed by Dianna Agron in the film adaptation of I Am Number Four.
The first day John sees Sarah, "she's shockingly beautiful with straight blond hair past her shoulders, ivory skin, high cheekbones, and soft blue eyes."
She was very polite and understanding, but is willing to do anything for the Garde. Sarah refused to betray any information to the Mogadorians, even after being beaten and tortured for weeks in Dulce. Number Six taught her how to shoot after they rescued her. Sarah was also very poetic and something short of a hipster; the last person she spoke to before she died was John.
She always supported John and made him believe that they would win.
In The Fate of Ten, it is alluded to that Sarah has developed the Legacy of telepathy. This is not explained much due to the dire nature of the situation. Six comments that "... Sarah is also tuned in to Ella's telepathic channel".
Sarah was a human born on Earth, and raised in Paradise, Ohio. She went to high school like an average human teenager, where she met Mark James. They dated for two years, but the relationship was detrimental to her. While drifting away from her family and friends, she started to adopt some of Mark's attitudes toward people: "being mean and judgmental, thinking she was better than them. She also started drinking and her grades slipped."
At the end of her sophomore year in high school, Sarah was sent to spend the summer in Colorado with her aunt. She started to enjoy nature and photography, "realizing there was far more to life than being a cheerleader and dating the quarterback of the football team." Returning to Paradise, Sarah broke up with Mark and quit cheerleading, making a vow to be kind to everyone. Apparently, the only thing she missed about being with Mark were his two dogs, Abby and Dozer.
She is first encountered by John as he enters the school for the first time. She remarks on how his hand feels hot when she shakes it, John later discovers this is due to his lumen. The next day, she is paired with John in home economics class and they eat their pancakes off a single plate instead of two like most of the pairs. She feels sorry for him for being bullied by Mark and informs him that they are no longer dating. However, she fills him in on their history, where the two were a couple and she dumped him after a vacation to Colorodo to rediscover herself. After his last period, just when he is getting ready to fight Mark, she returns with his phone, but first adds her number. After several weeks of them becoming good friends, they attend the Halloween festivities together and even go on the haunted hayride together with Sam Goode and Emily Knapp. When they are attacked, she is taken off and John finds her and attacks Mark and his friends. She and John slowly fall in love and he (without Henri as he is 'tied up' in Athens at the time) goes to her house for Thanksgiving. He accidently breaks her camera with his newly found telekinesis. He refuses to leave Paradise after the events in Athens because he loves her. Before Christmas, she goes for 10 days to Colorado with several of her friends to help rebuild an animal shelter. She and John kiss as the ball drops on New Year's. While attending a party at Mark's house, she is trapped upstairs with two dogs as a fire spreads through the house and John uses his Lumen to save them. He then admmits he is Loric to her and she accepts it. Two days later, the day she is meant to have her driving test, the Mogadorians find out about John and close off the school. She hides until he returns. She then hides inside under Henri's orders until his death where she is seen saving John along with Mark. When John awakens, she has helped him heal some of his wounds. They confess to loving each other one more time before he leaves, promising her he'll come back for her, even it it's the last thing he'll do.
John returns to Paradise with Six and Sam. He and Sam stop by her house and John texts her to meet him at the park. She meets him and the two of them argue over John's relationship with Six. Sarah receives a text message and tells John it is simply her friend Emily. After Sam joins the two out in the open Sarah receives another text message, this time ignoring it. Sarah then informs the two that she is aware of the danger they are in and steps away from them. As she does the FBI swarm them and Sam and John are taken away.
In the Rise of Nine, Sarah Hart is repeatedly mentioned by John Smith as he remembers that Sarah turned him into the FBI when he went to see her in the Power of Six. She is actually seen when Six, after being captured by the U.S government and thrown into a cell in an underground base in New Mexico where one of two Loric ships is hidden, Six is thrown into a cell with Sarah Hart, who has also been captured and questioned about her knowledge of Lorien and the Loric race, remaining Garde, and John Smith. Sarah explains to Six she never called or contacted the FBI to come and get John. She also confesses she is still in love with him, and always has been. Six and Sarah end on good terms before Six leaves to fight Setrakus Ra, the Mogadorian leader. Later, John and the rest of the united Garde break Sarah out of the cell just before going into battle against Setrakus Ra. She is told to guard Special Agent Walker, a female worker for the government who has paired up with the Mogadorians. Later, during the battle, she leaves her post and fires at Mogadorians with a canon, though John tells her to leave, she doesn't. She manages to bring a few down, but then Setrakus Ra strikes her and Ella with his whip, leaving them vulnerable after getting shot by another canon. John doesn't want them to die so much that he grabs both Ella's and Sarah's hands and triggers a new Legacy where he is able to heal, and therefore saves Ella and Sarah.
Sarah went to Nine`s penthouse and stayed there with the Garde. She went to Arizona with Number Four and Number Six. She came back, and was happy when there were more humans around. Six was teaching Sarah how to shoot crossbows and guns. She went on a walk with John and they met a few Mogs. John killed them and took the documents they carried. They went back to the penthouse. Sarah was very upset when John wouldn`t wake up. She fought when the Mogs invaded the penthouse.
Four, Sam, Adam, Malcolm, and Sarah fled to an abandoned factory. Sarah finds a website called They Walk Among Us, with a post about Mogadorians by someone called JollyRoger182. Sarah guesses that it is Mark James. They find out that apparently an important U.S. government member is in league with the Mogadorians. Sarah wants to email him. Adam makes her email difficult to trace. They find a bunch of emails from Mark, talking about a lead he has. Sarah goes to meet Mark, along with Bernie Kosar. Four just hears from her over the phone, saying that Commander Sharma had caught a Mog and that Mark had noticed some important information.
Sarah does not appear for most of the book. She, Mark and Lexa fly in Lexa's Loric ship to the Sanctuary in Mexico to help Six, Marina and Adam. When Six asks if she has developed any Legacies, she responds saying that she is "still a boring human". She kills many Mog soldiers and when Six fights Setrakus Ra alone, Sarah remains to help her. Six and Setrakus Ra use their Telekinesis to fight each other and Sarah is ultimately hit with flying chunks of debris. A large piece of debris takes a chunk of her mid-section. With Marina unconscious on board the Loric ship, Sarah cannot be healed. She calls John to say goodbye and she bleeds out and dies while speaking to him.
Because Mark is the only other human around at the battle of Paradise High who lived to tell the tale, Sarah is now only friends with Mark. At their new school, everyone thinks she is either crazy or weird, or both. They alienate her because she was with John Smith. Mark and Sarah usually go to lunch together, and drive home together as friends.
Both Mark and Sarah try to find information about where John is, especially after Agent Walker approaches them. At one point, Sarah texts Mark, telling him that John is back in Paradise. However, Mark's father sees the text and sends the authorities to go and apprehend John. Sarah leaves the police station the next morning, Mark picking her up.
They get chased by a black van while trying to break into Sam's house for information. Some time later, Walker comes to Mark's door, telling him that Sarah is missing. He gathers his things and goes on a mission to find her.