The ClueFinders: The Mystery of the Backlot Banshee is a short chapter book first printed in March, 2004. It is authored by Ellen Weiss and Mel Friedman. It is one of two ClueFinders books released by Learning Company Books, the other being The ClueFinders: The Mystery of Microsneezia.
The book contains several illustrations with interactive puzzles that the reader can solve to learn clues about the story. The book seems to be mainly aimed at 3rd and 4th graders, as it contains an advert for The ClueFinders 3rd Grade Adventures: Mystery of Mathra and The ClueFinders 4th Grade Adventures: Puzzle of the Pyramid in some of its last pages.
While the ClueFinders are vacationing in Los Angeles, Leslie spots a newspaper article about the production of a Hollywood film called The Doomsday Worm. The film is based on an autobiographical account of detective Perry Boston's capture of the genius computer hacker Morris Nogudnik. Movie star Jason Torch has been cast as Perry Boston, and shooting for the film is set to start as soon as a stunt double is found for Jason Torch. The stunt double must be skilled at skateboarding, and the article lists the time, date and location for the tryouts. Leslie excitedly shows the article to the other ClueFinders, and Joni exclaims that Perry Boston is her favorite detective, and that he even served as an inspiration for her and Santiago when they started the ClueFinders Club. Owen thinks he could qualify to be Jason Torch's stunt double, and Joni realizes that if Owen auditioned, it would give the ClueFinders a chance to see inside the studio and maybe even meet Jason Torch and Perry Boston.
On Friday morning, the ClueFinders all show up at Boffo Pictures studio early for the auditions, where they encounter a large crowd of people already waiting to be let inside the studio. The director and producer for the film, Wilton Thumbling, arrives right at eleven o' clock sharp, and leads all of the onlookers inside the studio to the movie set. There, his assistant Atilla provides the auditionees with jet-powered skateboards. Each auditionee must complete one lap on a roadway around the set on one of the jetboards, and the top three fastest finishers move on to an obstacle course afterwards. Owen makes it into the three final qualifiers. Wilton Thumbling tells them that they must chase after the stunt man playing Morris Nogudnik as he bounces down the road on a pogo stick until he reaches a gigantic video screen displaying a crossword puzzle, at which point they must catch him. Any mistakes made on the obstacle course will result in an automatic disqualification. Leslie asks Joni how the real Perry Boston apprehended Morris Nogudnik, and Joni explains that Morris Nogudnik was a word-game fanatic who could never stand to see words misspelled or crossword puzzles unsolved. This gave Perry Boston the idea to set up a crossword puzzle to appear on a video screen, and when Nogudnik stopped to solve it, Perry Boston seized the opportunity to arrest him.
The other two qualifiers try the obstacle course before Owen does, and each of them wipe out on different parts of it. When Owen starts skating through the obstacle course, he skillfully avoids every danger and distraction. As the crossword puzzle appears across the Jumbotron video screen and the stunt man takes his position, Owen skates towards him and prepares to catch him. Just then, a banshee appears on the video screen, which startles the stunt man and causes him to lose his grip on his pogo stick. Owen catches the stunt double and saves him from getting injured. On the screen, the banshee shrieks that the movie is doomed and all must leave the studio. Then an explosion occurs from the computer control room overhead, raining sparks down on the cast and crew below.
Joni, Leslie, and Santiago quickly rush up to the computer control room to help out. Joni reaches the room first and tosses a fire extinguisher to the computer operator so he can put the fire out. Then the ClueFinders look for a way to turn off the power in the room to prevent the short-circuiting wires from causing any more damage. Leslie also grabs the documents and disks from the room to salvage them. After firefighters arrive and put out the rest of the fire, Wilton Thumbling congratulates the ClueFinders on their quick thinking. Then Joni asks him if Owen got the part, which Wilton Thumbling confirms. As the ClueFinders cheer, the computer operator, Mr. Binckley, wonders if they could investigate the strange scenario which occurred earlier. Mr. Binckley claims that the Jumbotron must have been sabotaged to make the banshee appear on the screen, and he says that since the studio would rather avoid bad publicity by calling in the police, the ClueFinders could do some quiet sleuthing for them. The ClueFinders agree, under the condition that they can be allowed to go anywhere and question anyone who might be related to the case. Wilton Thumbling accepts their proposal and gives them a master key to all of the rooms in Boffo Pictures.
The ClueFinders start to explore Boffo Pictures, passing through various studios and coming across all kinds of actors and sets. As they approach a gate, they suddenly encounter a man dressed up in a space alien costume. The unknown costumed person says that he's read all about the ClueFinders and knows all about them, and then asks them what brought them to Boffo Pictures. Joni insists that they're too busy for questions, but the strange costumed man doesn't budge. Joni then fakes right before quickly dodging left and getting around him, and during his confusion, Leslie, Santiago, and LapTrap rush by him. Once they are out of earshot of the costumed man, Joni and Santiago both agree that he was creepy, and Leslie expresses sincere doubt that he was a ClueFinders fan. However, much to their shock, Owen remained behind to talk to the stranger, who took out a notepad to jot down what Owen was saying. As the other ClueFinders rush back to confront the costumed man, he runs away towards a brick building. Owen catches up to him first, but the alien appears to go straight through a brick wall, leaving the ClueFinders stunned. Joni turns to Owen and asks what he told the stranger, and Owen sheepishly admits that he revealed almost everything about the audition.