After Riz and her friends successfully led the Counterfeit Bust, Riz has discovered her passion for forensic science. One day at school, she finds the perfect opportunity to break out her new forensics kit and solve a new mystery. On their way to class in the morning, Riz and her friends notice a commotion outside the music room and hear that something has been stolen! They head off to class, but Riz's observation skills allow her to notice the principal, deputy, office staff, and their music teacher speaking with removalists outside the classroom window. Riz tries to lipread their conversation and deciphers it at break with the help of her friends and Peiter from Grade 6. Instruments have been stolen from the music room in the midst of its renovations! They start their investigation by sneaking into the music room and finding some fingerprints. Riz and her friends collect the fingerprints of all their classmates and compare the patterns, promising their teacher to give the class a presentation on their findings. They break off into teams to collect even more fingerprints at break, from other Grades, and even from their principal! They finally find their match, but before they can bring the information to anyone else, the deputy principal pulls them in for a stern chat.

Will they solve another mystery? Another forensic science inspired story for young readers.