Ten-year-old twins Maddie and Mia and their younger sister, Lulu, travel with their dad and famous mom, Gloria Glimmer, to London, where Gloria is putting on a few concerts. During their stay, they get to see the sights, including the National Gallery, to which Maddie is drawn due to her quieter, artistic bent. While there, Maddie and Mia see what they believe is the theft of a Renoir painting. When no one believes them, Maddie sneaks out of the hotel one afternoon to catch the thief. Blending travelogue, mystery, and family story, this novel from Christian recording artist Grant has pedantic overtones, particularly in the interactions between Maddie and her mom, that may turn off some readers. Still, the story will find a home with many conservative Christians and fans of Grant's music. First in the Glimmer Girls series, this light mystery gets some added sparkle as the book's adults encourage Maddie to find her own "glimmer."