Nick is more than a little concerned. The entire natural area of Carthage—the Mississippi River, the parks, the woods, everything "green and brown," as he puts it—has been torn apart, dragged, and thoroughly searched with no trace of Amy. It's Nick's theory that if she was going to be found, nature would have to reveal her, and that doesn't seem to be happening any time soon.
The lack of leads in the case also seems to be making people pretty callous and insensitive toward Nick. When he arrives at the volunteer center, he overhears someone expressing his theory that the killer chopped up Amy's body and threw it in the river; another volunteer greets Nick by telling him that a drunk driver killed his daughter, which means he totally gets Nick's position. Seriously, people—have some respect for this poor man who may or may not be behind Amy's disappearance.
Nick's disposable cell phone rings and he doesn't take the call, which is weird, because first of all, his wife's missing and the call could be important, and second, it's a disposable cell phone.
Marybeth hurries up to him and asks if he can drive to Memphis, where Hilary Handy lives. While the police don't think it's a lead, Marybeth insists that Hilary maintained creepy, stalkerish contact with Amy for years—Nick agrees to go, and he'll stop off in St. Louis to check out Desi as well.
Stucks comes up to Nick holding a donut and tells him he's mad because the cops went to the mall… during the day. Here's the problem with this: all the shady characters come out at night, like vampires and werewolves. Stucks decides that he, Nick, and the Hillsam brothers—the town bad boys—are going to go on a vigilante mission to the mall that night to see if they can get any hits. During their conversation, Nick's disposable phone rings again, and again he doesn't answer it. Who keeps calling Nick?
After the volunteers disperse for the day, Nick meets up with Rand and Marybeth to brief them about the mall visit. Rand says he wants to come along, and while Nick has a hard time picturing Amy's goody-goody dad being one of the bad boys, he says that he may of course come.
Because the panties Gilpin found at Nick's office got him all jazzed up, he forgot to take Amy's second clue as evidence. Amy's seriously taken things easy on Nick with this year's scavenger hunt, and he figures out instantly that she's writing about Hannibal, Missouri in this clue, Mark Twain's hometown where Nick used to dress up as Huck Finn for a summer job. While the last line about kissing and pretending they "just got hitched" is a mystery to him, he heads out to Hannibal to retrace the steps of the trip they made there the year before.
Nick wanders around Hannibal taking in the local historical sights, including a guy dressed as Mark Twain getting out of a Ford Focus; he tries to get a lead on Amy's clue. When he passes by the sign for Mark Twain's father's courthouse advertising the Justice of the Peace, the clue immediately makes sense—he locates the next clue inside, as well as another note, taped underneath a nearby bench.
Amy's note describes how she's come to realize over the last year that the scavenger hunt should be a celebration of their marriage, not a showcase of her random memories. She also showers Nick with compliments and sexy memories in a way that makes him uncomfortable. Here she is, trying to win him over and give their relationship a new start—and she's gone.
Nick reads the next clue, and again knows just where to go. He says, though, that he isn't ready to look yet; there will probably be another glowing note with the next clue and he doesn't think he can handle more of that.
Nick goes back to Go's place, where he fills her in on the field trip to the mall taking place that evening. He doesn't mention the trip to Hannibal because Amy's act of kindness is too guilt inducing, though he does tell Go that he doesn't think he's been upset about Amy's disappearance, and she agrees. She warns him to be careful about how he acts around others in order to avoid being unfairly judged… kind of like Marybeth and Boney seem to be doing.
At exactly 11:08PM, Rand shows up outside the Days Inn to meet the rest of the crew for the midnight voyage to the mall. On the way, while riding in the back of the Hillsams' pickup truck, Stucks tells Nick an obviously fabricated story about Amy going to get him a cold drink while he was painting a house on a hot day—Nick knows this is bogus because Amy couldn't stand Stucks.
The mall is one heck of a creepy place. It smells like nature inside, there are homeless people camping out everywhere, and a raccoon has moved into the women's restroom. Almost immediately, the gang launches into a high-speed chase sequence after one of the alleged Blue Book Boys, during which they trip over a sleeping homeless couple.
They finally end up in Mervyn's, one of the cornerstone department stores that has been taken over by druggies and weirdos. They confront the Blue Book Boys about Amy's disappearance and get in a slight tangle with their leader, Lonnie, which abruptly ends when Nick pulls out Amy's picture to show them. They are immediately silent. Lonnie informs Nick that he has indeed seen Amy—she approached him once about buying a gun.