Marie Curious, Girl Genius: Rescues a Rock Star : Book 2

Marie is reunited with her geek girl friends when Sterling Vance invites them to present their winning invention at a big tech fair in London. There, the four young female scientists befriend a young pop star, whose tour Vance is sponsoring. She's unhappy with the way her management is making her try to be someone she's not. When the pop star disappears on the eve of her high-tech world tour, it's up to Marie and her friends to track her down so the show can go on.