Rosie and her best mates Soph and Abs are three regular girls. They like regular-girl things; they eat regular-girl food and wear regular-girl gear. In book one in the "Megastar Mysteries" series, their regular-girl lives are turned upside down when Rosie gets caught up with a desperate plea for help from a mega pop star, Mirage Mullins, who's doing a signing in their local record shop. The girls don't know quite what to do, but they'll go to any lengths to help save the career of their favourite pop star. The trio of friends must find a way to solve the murky mystery surrounding Mirage's gorgeous stepbrother, Joe, and they resolve to get to the bottom of the strange behaviour of Mirage's manager, Simone Jones. Over the course of the "Megastar Mysteries" series, Rosie and her friends unintentionally stumble upon other celebrity mysteries that need solving and, much to their delight, are always finding themselves in demand by mega stars with mega problems. The girls help rising West End star Estelle realise that family's more important than fame, conspire to keep the ending of famous author Hollie's latest novel under wraps, and foil a plan to sabotage of child actress Scarlett's new singing career.