Claudia is excited because a new museum is going to be opening in Stoneybrook. There will also be an exhibit of sculptures made by one of Claudia’s favorite artists, Don Newman. Since most of the museum will be kid-friendly, Claudia decides to take Marilyn & Carolyn Arnold and Corrie Addison with her to check out the museum. After looking at some fun, hands-on kid-friendly things for the kids to enjoy in the science & music rooms, Claudia takes the girls to the Newman exhibit.
On their way there, the fire alarm goes off and Claudia takes the girls out and as they reach the exit, another alarm goes over, but it’s different from the fire alarm and it sounds to Claudia like the alarms that are attached to arts & artifacts that aren’t allowed to be touch. A guard tells everyone that some valuable coins have been stolen and that everyone will have to be searched before they can leave the museum. Claudia and the girls make it through the search and Claudia leaves the museum hoping to solve the mystery.
The next day at the BSC meeting, the girls talk about the robbery. They go over everything that happened to Claudia and the kids & they decide to go back to the museum as a group the next day to stake the place out in order to figure out where the thief might have stashed the coins. Mallory thinks that they’re still in the museum somewhere since everybody was searched and the coins weren’t found. Claudia thinks that the coins might’ve been dropped into the donation box, but it’s not possible because the box is emptied every night. Claudia also thinks that the coins might’ve been hidden with some souvenir coins from the museum gift shop, but they aren’t because the souvenir coins are made from chocolate.
Jessi thinks that the thief threw the coins into the fountain, but they aren’t there. Stacey & Claudia decide to stay and they take a look at the Don Newman sculptures. Since Newman likes his art to be interactive, the museum actually welcomes visitors to touch his pieces. Claudia and Stacey touch just about all of the pieces, but when Claudia comes to one of her favorite pieces, she gets suspicious. She had touched it before in New York and it feels different than it did that time. Claudia thinks it’s a fake and they go over to the curator, Mr. Snipes’ office to talk to him, but he’s mean to the girls which makes Claudia more suspicious. She takes a copy of Mr. Snipes’ resume off his desk when nobody’s looking in order to find out more about him.
The next day, the girls get together at Claudia’s house to talk about the mystery. Even though Claudia threw away Mr. Snipes’ resume in the trash without looking at it, after the girls & Logan start talking about how creepy Mr. Snipes seemed, Claudia shows it to them. They go over to the library to do some research on the museums that were listed on the document. They discover that all but one of the museums listed had a robbery during Mr. Snipes’ time there.
Claudia realizes that she got a pretty good look at the broken glass case right after the robbery and there was glass all over the inside of it. If the glass had been broken before the robbery occurred, there would’ve been blank spaces where the coins had been which makes Claudia realize that the person who stole the coins must’ve had a key to the case making it an inside job.
Claudia is still convinced that the Newman sculpture is a fake, so after getting Newman’s phone number from information, she calls him at home. Newman tells Claudia that the sculpture probably felt different to her because he built little hiding places and secret compartments into a lot of his work so he could hide surprises in there for his kids. Claudia loves that idea, but less than a year had passed between her two viewings of the piece & Newman definitely hadn’t hidden anything in there during that time. Newman invites Claudia & her parents to a formal party at the museum the following night in honor of the end of his exhibit so they can check the sculpture out together.
During the party, Claudia tells Newman about how suspicious she has been of Mr. Snipes. They decide to follow Mr. Snipes after they notice him leaving the party, but all he does is go into his office. Then they head to the room where the sculpture is displayed, but they find out it’s been moved to a storage room already. Claudia and Newman head to the storage room, but they hide when they hear somebody coming which is the janitor. They watch as the janitor reaches inside the sculpture and pulls out the missing coins.
When the janitor turns to leave, he notices that he’s being watched and tries to make a break for it, but Newman tackles him. Somebody else, who turns out to be a Federal agent tackles Newman. It is discovered that the custodian wasn’t really a custodian: he was a thief who had been planning to take the coins since the museum first opened. He was planning on selling them to a museum in Switzerland & retire on the proceeds of the sale, but the museum had been tipped off in advance that might be vulnerable to theft which is where Mr. Snipes entered the picture. Mr. Snipes specializes in preventing robberies which is why he was brought to Stoneybrook to work at their museum. Claudia gets a write-up in the newspaper for her role in the case and she is made an honorary trustee of the museum.
Claire Pike has decided that she wants to be in show business. She gets a video made of herself singing "Somewhere Over the Rainbow" at Washington Mall and even sends the video to an agent, but it gets rejected. After a talk with Jessi about what it's really like being in show business, Claire decides that she doesn't want to be in it anymore.
Claudia can't wait for the new museum in Stoneybrook to open They're featuring an exhibit of her favorite sculptor.
But while Claudia's visiting the museum, someone steals some priceless coins! And later when she's looking at the sculptures, Claudia is sure that one of them is a fake.
Burglaries, forgeries — something nasty is going on in little Stoneybrook. But Claudia and the BSC are on the case!