The book starts off with two nine-year-olds Margo Spiegelman and Quentin Jacobsen come across a dead body while playing at the park. They rush home to tell their parents and eventually find out that the body was Robert Joyners a divorced man who had committed suicide. Margo wonders why he had committed suicide and Quentin just tries to forget about the entire thing. The book then flashes forward to highschool Margo and Quentin who have grown apart since that day at the park. One night out of the blue Margo shows up at Quentin’s window and asks if he wants to join her on her mission to get revenge on some people. They go prank everyone who has ever messed with them in school and Margo’s ex-boyfriend. When they get back Quentin lays in bed and think that the two have started bonding and might become friends again. The next morning he had found out that Margo has left, leaving a trail of clues behind her. Quentin and his two friends Ben and Radar are all stressing about finals and looking for clues that Margo has left so that they can find her. The first clue that they had found was a poem by Walt Whitman which lead Quentin and the boys to an abandoned mall. At the mall, they find clues that Quentin thinks leads to Margo’s hideout spots. Quentin than thinks that maybe Margo had killed herself and wanted him to find her. Finally, he finds a map of the United States. He notices that on the map New York is pinpointed. After a while, he notices that the holes on the map align with the hole he saw at the abandoned mall. Only one hole actually lines up with a city called Agloe, New York. He googles Agloe, New York to try and find some things out about this city. Quentin sees that someone has commented stating that the population will actually be one until May 29th at noon. He believes that Margo was the one who had posted it and thinks that where she is staying for the time being. He gathers up his friends and Margo’s best friend Lucy to go on a journey to find her. All of them skipped their high school graduation to take a trip to Agloe, New York to go get Margo. They have one whole day to go and Margo before she’s gone. On the way there they experience many problems and almost died. Once they finally arrive in Agloe the find Margo in an abandoned barn-like building. She seemed like a totally different person than who she used to be. She got mad at her friends for coming to get her but if she didn’t want anyone to find her then why did she leave the clue in the first place? Margo seems more upset than mad that her friends had come to find her. They all see who Margo really is and are confused. They realize that not everyone is who you think they are. Margo has decided that since she has graduated she is just gonna go travel the world and find herself. Quentin realizes that he and Margo will be nothing more than friends and than they kiss goodbye.