Nancy, Bess, and Ned are sitting around eating Chinese food and talking when Ned tells them that his class is taking a field trip to the local prison. To help them better understand white collar crimes, their professor wants them to talk with real inmates. Bess remembers that their friend Lisa's brother is there because he got caught laundering money through Over the Rainbow, a local comedy club. Before she can even ask, Ned lets Nancy know that he already cleared it with his professor for her to come along.
They meet a money launderer who tells them all about how he made illegal money gambling and tried to launder it through the grocery store he owned. Matt, Lisa's brother, then catches her eye and waves her over. He tells Nancy that he absolutely did not embezzle or laundry money and begs her to help. Matt also tells her that the only person he suspects is his former junior partner Peter Sands.
The next night, Ned stops by to pick Nancy up and take her to a party. A white van comes out of nowhere and almost pushes them off the road, but he gets the car under control. Ned then realizes that he saw the van earlier in the parking lot of his college. Bess introduces Lisa to Nancy, but the girl seems really cool, especially when Nancy brings up Peter's name. Though she swears she believes her brother is innocent, she seems less than happy that Nancy is helping and really can't give them much information. She supposedly even has a hard time remembering the name of his lawyer.
Since Nancy wants to get a closer look at the club and Bess has some type of connection, she suggests that Nancy get a job as a waitress. They head to Over the Rainbow and get inside, which is where they overhear a woman saying that if anyone leaks “it” that Johnny will kill them all. The same woman then notices Nancy and introduces herself as Bianca, one of the club's managers. She also introduces them to the other manager, Tony, before hiring Nancy on the spot. Wow, I never knew it was that easy to get a job in a popular club.
They randomly run into this guy Rusty and his partner as they're going over their act. Bess jumps in, they do the whole performance, and he hires her to fill in while his partner is out of town. The girls also notice an older well dressed couple parking in the comedy club lot before going to a dance club. Nancy finds it weird since the club is more popular with younger people and is pretty casual.
She spends the next day checking things out. The woman who swore Matt opened a new account at her bank unexpectedly won a trip to Hawaii and left town. Matt's lawyer isn't sure he did it but can't remember much about the case. He did get two handwriting experts to come in, and both agreed that the embezzlement paperwork was signed by Matt. She also meets his PI. The man is more interested in flirting with her than doing any help, but he does say that he thinks Matt is innocent. Her and Nancy go to see Peter and find Lisa there. Lisa acts super embarrassed and takes off, and Peter claims she's doing an internship with him. Is that what the kids are calling it now?
When Nancy finally goes to work that night, she gets the chance to spend some alone time in the office. It's there that she finds paperwork that includes a receipt for multiple bottles of champagne, which is weird because the club doesn't serve alcohol. She then finds receipts for poker chips and playing cards, which she thinks is proof the club operates an illegal gambling casino.
Keith, the PI, stops by the club to flirt with her some more, and she gets to meet Johnny, the club's owner. When she sneaks back into the office, she finds an accounting book, but someone then hits her over the head and knocks her out. Yes, again. She comes to, tells Bess what happened, and then runs to tell Ned too. He decides that he should probably stick close to her from now on. Good idea.
The next morning, they drive over to Bianca's apartment and then follow her as she picks up Tony and then to the warehouse district. Nancy approaches them and pretends she was just out for a drive. Bianca acts super shifty and says they just needed to pick up some club supplies before they make an excuse to leave. Nancy then talks to the guy at the front door of the warehouse about buying poker supplies, and he tells her that the only see wholesale in bulk.
The two then go to meet Carla, the bank lady who swears Matt opened an account with her. She acts shady as well, telling them that she really doesn't want to go over everything yet again. Carla just says she gave him a receipt and identified him in court. When Nancy asks about her trip, the woman lights up and says it was amazing. She also says that her uncle paid for her trip, which is odd since she supposedly won it.
Determined to find more evidence, Nancy sneaks over to Peter's office. She finds a book that has all the travel receipts for Over the Rainbow in it. Just as she finds proof that the club paid for Carla's trip, Lisa bursts into the room and demands to know what she's doing there. In like 30 seconds, she breaks down and says that she started dating Peter right around the time her brother got arrested and now she thinks he set him up.
Cut to Peter walking in the room. They tell him everything, and he's all shocked. He confesses to finding some suspicious receipts but says he really believed it all pointed to Matt being guilty. Peter even lets them go through his files. Ned comes in when he sees Peter leaving and finds a receipt for a company called Allen Associates. When they call the number, it doesn't exist.
Nancy and Ned then go to Carla again. She finally breaks down and says that he lied on the stand to get a free vacation. Someone really did open the account but it wasn't Matt. While on the way back to her house, they see the same white van and follow it. The van stops at a warehouse, guys climb out, they pick up a bunch of gaming tables, and then take off again. Nancy and Ned lose them and head back to the warehouse. Ned pretends that he's one of the guys and finds the address they were on their way to.
Nancy thinks there is something weird about the hip dance club near the comedy club. While checking it out, someone grabs her from behind. It's Keith who wants to flirt some more and drops no new information. She then goes into work and gets a call from Ned. He tells her that he tracked down Allen Associates and that it doesn't exist. The address is just an empty lot. Before he can tell her anything else, she realizes that someone is listening in on the call.
Bianca acts completely cold to her, which makes her think she was the one on the phone. She then overhears Bianca and Tony having a fight over a receipt. Tony tells her that it's too big, that she needs to make it smaller to be believable, and then warns her to put it away before Johnny catches them. When Nancy learns from Johnny that there are private rooms upstairs for rent and both are rented, she sneaks her way up there. The bouncer originally refuses to let her in but then agrees to let her look around a bit. To no one's surprise, she finds that the rooms are filled with gambling equipment and people in fancy clothing.
That's when she notices Keith. It suddenly comes to her that Keith knew Johnny for a long time and that there were rumors of Johnny laundering money through the club. She sneaks away before he can see her and winds up in a long hallway that seems to lead to nowhere. When she finds a light, she follows it, opens a trap door, and suddenly finds herself on stage in the comedy club.
Everyone thinks it's hilarious, and Rusty even wants to write it into his show. Johnny stops her and seems confused about where she came from and where the tunnel goes. Nancy makes up an excuse and rushes to the office. This time, she finds a hidden drawer that has all the records for the illegal casino. Bianca catches her but denies she had anything to do with the casino and puts the blame on Johnny.
Bianca even has Tony come in to talk to her. It turns out that they were planning a secret party for a friend at the club. Johnny wouldn't let employees use the club for personal reasons so they kept it a secret from him. They even show her that all the boxes she saw them with are boxes of party decorations and invitations. The phone then rings. Nancy hears Bess crying and then hears Keith threaten her that unless she backs off, she'll never see her friend again.
Nancy bluffs and says that Carla will admit she lied and identify Keith as the man who opened the account. He tells her that unless she meets him in the morning and trades the documents for Bess, he'll kill her. Both Bianca and Tony convince her that getting Bess back is more important than bringing down the bad guys. She gets a note the next morning to meet at a burned down club, but she first goes to the private rooms and finds that someone cleared out all the evidence the night before.
The only thing left is a single poker chip. Bianca then steps out of the shadows and says she got there early to look for proof too. They hear a knocking sound, which Nancy realizes is Bess trying to get their attention. The trio follow the noises until they find Bess tied up and gagged. Keith steps into the room with a gun, Ned tells him it's four against one, and then Johnny steps in with a gun of his own.
Johnny herds them all into a different room and gives them the chance to ask any questions they have. Nice guy, right? Nancy asks if it was all his idea, and he admits that he had friends in Vegas who wanted to expand their operations and that Over the Rainbow seemed like the perfect place. Tony accidentally wanders in, and Johnny tells him he's sorry that he has to kill him now too. He keeps talking and doesn't notice as Tony and Ned get closer to them. They jump the guys and hold them down while Bess runs to call the police.
At the end of the book, they hold a welcome home party for Matt. Bianca and Tony announce that they're going to take out a loan and buy the club and ask Bess if she'll come back sometimes and do her performances on stage. They all celebrate Matt walking in the door. Ned tells Nancy that she's the best detective in River Heights and his favorite person in the world before kissing her. Aw.
*I love that Bess drives a red Camaro. It somehow seems to fit with her personality.
*Nancy dresses “up” for the party, which means she wears a blue sweater that matches her eyes and jeans that hug her body.
*Hannah makes fruit salad, cheese omelets, hash browns, and like six other things just so Nancy and Ned can eat breakfast together.
*It's nice to know that Carla was willing to put a man behind bars for years in exchange for a three week trip to Hawaii.
*The end is a little weird because Nancy says that Matt's lawyer is working with the authorities to get him out of prison soon. He literally walks into the room on the next page. I'm pretty sure it takes a little longer to exonerate a person.