Evan Hansen is a teenager who struggles with severe social anxiety which makes it hard for him to make friends. His therapist recommends that he write letters to himself detailing what will be good about each day. Before the first day of his senior year in high school, his mother, Heidi, suggests that he make new friends by asking people to sign the cast on his arm, which he broke by falling out of a tree over the summer.
Across town, the wealthy Murphy family — Cynthia, Larry, and their children Zoe and Connor — sit down to breakfast. Zoe and Larry berate Connor for getting high before school, while Cynthia struggles with the fact that her family is falling apart. The two mothers wonder simultaneously how to connect with their sons ("Anybody Have a Map?").
At school, Evan runs into Alana, a smart classmate, and Jared, the son of a family friend and the closest thing Evan has to an actual friend. Both Alana and Jared notice his broken arm, but neither signs his cast. Instead, Jared teases Evan about it. Jared and Evan then encounter Connor Murphy, whom Jared pokes fun at. Connor interprets Evan's awkward presence as laughing at him, resulting in him pushing Evan. Connor's sister Zoe, who Evan has a massive crush on, feels obligated to apologize for her brother's behavior. Evan wonders if this is his destiny – to be ignored and an outcast, never to get the girl of his dreams; "on the outside always looking in" for the rest of his life ("Waving Through A Window").
Evan writes himself another letter. He states he has given up on it being a good year and how he wonders if anyone would notice if he were not there. He remarks that all his hope is now pinned on Zoe. While printing the letter in the school's computer lab, he encounters Connor again, who asks what happened to his arm and offers to sign Evan's cast, musing that maybe now they can both pretend they have friends. After signing the cast, he reads Evan's letter (which he grabbed from the printer as a favor) and becomes furious at the mention of Zoe, thinking Evan intended for him to see the letter in order to make fun of him. He storms out, taking the letter with him.
Several days pass with no sign of Connor. Evan is in an intense state of anxiety over what Connor might have done with the letter, and tells Jared online about his assignment to write letters to himself, and how he's worried about what Conner might've done with the letter. Jared remarks that Conner has always been completely out of his mind. Later that day, Evan is called to the principal's office, where Connor's parents are waiting to meet him. They tell Evan that Connor died by suicide a few days before with Evan's letter in his pocket. Believing it to be Connor's suicide note addressed to Evan, they ask Evan if he and Connor were close, as Connor had never mentioned having friends before. Not wanting to further their grief and unsure what to do, Evan agrees to go to their house to talk about Connor. There, after seeing Cynthia's distress over the loss of her son, Evan panics and, rather than telling the truth, begins to fabricate an intricate story of his and Connor's friendship, claiming he and Connor kept up a secret email correspondence and recounting a fictional version of the day he broke his arm in which Connor was with him ("For Forever"). Later, Heidi reminds Evan that he needs to begin applying for college scholarships. She mentions hearing about Connor's death, but Evan tells her not to worry and that he didn't know Connor. Seeing Connor's name signed on his cast, Heidi confronts Evan, but he lies, saying that someone else named Connor signed it. After realizing he needs evidence of his supposed "secret email account," Evan enlists Jared's help in creating fake, backdated email conversations between himself and Conner ("Sincerely, Me").
After Evan shows the Murphy family Connor's 'emails', Cynthia is ecstatic that her son had a friend, but Larry is more hurt that Connor took his family and his privileged life for granted; Zoe, who was alienated by Connor's aggressive behavior and claims she does not miss him, refuses to mourn him at all ("Requiem"). However, after reading the suicide note, Zoe notices that she is mentioned and asks Evan why Conner would say that about her; Evan, unable to tell her the truth, tells her all the reasons he loves her under the guise of Connor saying them ("If I Could Tell Her"). Overcome with emotion, he impulsively kisses Zoe, but she pulls away and tells him to leave.
At school, Evan notices that people are starting to forget about Connor. Spurred on by a vision of Connor, Evan enlists Alana and Jared's help in founding "The Connor Project" — an organization dedicated to keeping Connor's memory alive. The three pitch the idea to the Murphys, who agree to support the project ("Disappear"); moved by his dedication, Cynthia gives Evan a necktie she had gotten for Conner that he had never worn, and asks Evan to wear it when he speaks at Connor's memorial service, which he hesitantly accepts. At the official launch of The Connor Project, Evan gives an inspiring speech about his loneliness and friendship with Connor, which goes viral. Zoe, overcome by the impact her brother and Evan have had, kisses him ("You Will Be Found").
Evan and Alana pitch a fundraising idea on The Connor Project's website. In memory of Connor, they want to raise $50,000 in three weeks to reopen the abandoned apple orchard that Evan and Connor supposedly spent time in. Evan, however, preoccupied with his new relationship with Zoe and his newfound family in the Murphys, begins to neglect his mother, Jared, and The Connor Project.
Heidi tells Evan that she saw the video of his speech on Facebook and asks him why he did not tell her about The Connor Project or about his and Connor's friendship. He then, angrily responds that he did not have the time because she is never around. Overcome with emotion, he then rushes off to the Murphys', telling her that he is going to Jared's. At the Murphys', Evan bonds with Larry Murphy and confides in him that his father left when he was young, has remarried, and no longer keeps in touch with him or Heidi ("To Break in a Glove"). Sometime later, at Evan's house, Evan makes an offhand comment to Zoe about how he and his mother do not have much money and he needs the scholarships to pay for college. When he begins to mention Connor, Zoe tells him that she does not want their relationship to be about Connor, but about the two of them ("Only Us").
Evan gets into a fight with Jared, who claims that Connor's death was the best thing that ever happened to Evan – he is no longer invisible and has landed the girl of his dreams. Later on, Evan goes to the Murphys', only to discover that they have invited Heidi for dinner. Heidi, who has no idea that Evan had spent time at the Murphys', is mortified when Larry and Cynthia offer to use the money that they had set aside for Connor's college fund to send Evan to school instead. After returning home, Heidi and Evan fight over his secrecy. When Heidi protests that the Murphys are not Evan's family, Evan confesses that he feels not only welcomed but also accepted by the Murphys in light of Heidi's absence and expectations towards Evan's mental health. Heidi tearfully berates him for running off to his new family, while Alana begins to find inconsistencies in the fake emails Evan "received" from Connor and suspects that the entire story is a lie. Beginning to panic, Evan urges Jared to help him clear up the inaccuracies, but Jared refuses due to Evan's own absence. Evan counters that Jared himself had acted as a friend to him only when he needed something from him. Jared threatens to expose Evan, and Evan warns him he could, in turn, open up about Jared's role. All three converge in Evan's conscience, compounding his guilt and doubt over his decisions ("Good for You").
Evan decides he has to come clean with what he has done. Imaginary Connor attempts to talk him out of it, citing the happiness he has given the Murphys and the fate of Evan's relationship with Zoe, but Evan does not back down, angrily shouting he needs the whole thing to be over. Connor is unconvinced and asks Evan how he broke his arm: did he fall by accident or actually let go? Evan denies intent, but Connor tells him that if he tells the truth, all he has will be gone, and the only thing he will be left with is himself. He disappears, leaving Evan alone.
Evan goes to apologize to Alana, but she says she has given up on Evan helping her with The Connor Project. She doubts the truth of Evan's repeated statements that he was Connor's best friend, since they were never seen together, and she says that it is easy to create fake backdated emails. Desperate, Evan says he has proof that they were friends. He shows her the letter to himself that he wrote when he was giving up on having a good year, claiming it to be Connor's suicide note. Realizing that the letter is the key to fulfilling the fundraising goal, Alana posts it online, to Evan's chagrin, and it goes viral. As a result, however, many people begin to believe Connor's suicide was because of his uncaring parents.
Evan is distraught and goes to see the Murphys, who have become the targets of hateful comments from people who believe they were responsible for Connor's death. He walks in on the three of them fighting about why Connor really killed himself and finally admits that he fabricated the entire thing, hopeful that he could forge a genuine bond with the Murphys out of the tragedy. As Zoe and her mother tearfully run out, Larry turns away from Evan in disgust. Alone once more, Evan absorbs his perceived brokenness as inescapable ("Words Fail").
Evan finds Heidi waiting for him at home, who saw the letter online, immediately knowing that it was one of Evan's therapy assignments. She apologizes to Evan for not seeing how badly he had been hurting, though Evan denies her guilt due to his deception. He then vaguely admits that his fall was a suicide attempt. Heidi sits him down and recalls the day that his father moved out: how she felt so small and alone and did not know how she was going to make it by herself. In the end, however, she realized that she was not alone – she had Evan and knew that the two of them could make it through anything so long as they were together. Tearfully, Heidi promises that she will always be there for him when he needs her ("So Big/So Small").
A year later, Evan is still living at home and working at Pottery Barn to earn enough money to go to college the next semester. He contacts Zoe, whom he has not seen since she found out the truth, asking if she will agree to meet him. She does, but insists that they meet at the orchard that has been reopened in Connor's memory. He apologizes for the pain he caused her family and admits that he has been reading Connor's ten favorite books after finding a list in an old yearbook in an attempt to connect with who he really was. He also thanks her and her parents for keeping his secret and revealing that they never told anyone else that his friendship with Connor was a lie. She forgives him, saying the whole ordeal brought her family closer together over the past year because "everyone needed it for something." Evan asks her why she insisted on meeting at the orchard, and she replies that she wanted to be sure he saw it, and the two share a gentle moment before they awkwardly part. Evan mentally writes himself one last letter reflecting on the impact he has had on his community and finally accepts himself ("Finale").
Check back soon when libretto and/or lyrics for Dear Evan Hansen becomes available.