Ben and Radar drop Quentin off at home, they return to school for band practice. Quentin gets worked up about what happened that morning and calls Detective Warren to tell him all about the clues, including the abandoned mall. Detective Warren tells Quentin to stop looking for Margo because Margo is an adult who can take care of herself. He warns Quentin that in searching for Margo, Quentin could lose himself. Quentin searches the Internet for more information about paper towns, and finds that a paper town is another name for a pseudovision. This, along with the morbid Walt Whitman poem lines, makes Quentin surer that Margo has killed herself. Radar and Ben both tell Quentin not to worry so much, and that Margo is selfish for wanting this attention in their last weeks of high school.
Quentin decides that he will explore a couple of pseudovisions nearby for clues, so after school, he borrows Ben’s car and drives to two of them. In the second one, he sees an oak tree and remembers the dead man that he and Margo had found slumped against one when they were kids. Quentin pictures Margo lying there, dead, but he doesn’t find anything, and instead starts to cry because he misses her.
At school on Friday, Quentin tells his friends that he found nothing at the pseudovisions, and Lacey starts to cry when she brings up the theory that Margo has committed suicide. Quentin shows his English teacher, Dr. Holden, Margo’s copy of Leaves of Grass, and asks for her help analyzing what Margo highlighted. Dr. Holden tells him that the poem is about valuing life, not ending it, and that it’s important to read the poem as a whole to understand that. This advice does not make Quentin feel any better. The next morning, Quentin gets annoyed that Ben and Radar are both absorbed in getting ready for prom, which is that night. Quentin lies to his parents and tells them that he needs the minivan to pick up a tux because he’s decided to go to prom. Instead, he drives out to more pseudovisions to look for Margo. He doesn’t find anything.
Quentin drives back to the abandoned minimall, and sees that the hole in the particleboard that they had made is taped up. He also immediately realizes that he hadn’t needed to break into the building after all, because he, Radar, and Ben had pulled on the doors when the doors actually opened inwards. Quentin returns to the abandoned office with a flashlight, and he realizes that one of the desk’s calendars had been switched from February 1986 to June 1986. In that desk’s drawer, Quentin finds a bottle of nail polish that’s the same shade Margo had used on the night of their adventure. Quentin sees a tiny smear of blue spray paint on the bottle, so he knows it’s hers, and realizes that she must have stayed in the building sometime after their adventure.
Quentin explores the space more thoroughly. He finds nine thumbtack holes on the wall, an empty box of nutrition bars, and a blanket that smells like Margo, and imagines her spending time there. Quentin calls his parents and tells them that he’s staying with Ben after prom, but, despite the rats, he settles down to camp out in the Troll Hole. Without Internet or TV to distract him, Quentin reads “Song of Myself” from Leaves of Grass, and although he’s gone through it over and over, he begins to understand it this time. As he thinks about what the grass in the poem could symbolize, Quentin declares out loud that he will find something in this minimall. He looks around some more and does find something: a travel guide published in 1998, long after the mall had been abandoned. Once he sees the travel guide, he discovers several more above the bookshelves, all published after 1986, and concludes that Margo had brought them there.
At 3:18 am, Quentin wakes up to a phone call from Ben, who is drunk at an after-prom party and needs a designated driver. Quentin leaves the minimall and arrives at Becca’s house just before four, where Ben is in the middle of setting a record doing a keg stand. Apparently, Ben is really good at doing keg stands, although Quentin knows that Ben has never gotten drunk before. Everyone at the party is drunk and sentimental, and even Chuck Parson says that he has respect for Quentin. Quentin is bored and annoyed, and he wanders down to the basement, where he sees Becca and Jase making out on her bed. Jase calls Becca Margo by accident, which makes Becca furious.