When a priceless sculpture disappears from the Capitol City Art Museum, thirteen-year-old Clementine Wim, daughter of an assistant curator, and her three friends set out to solve the mystery and recover the Statue of Gudea.
When the plans for the Bat-Wing, a historical aircraft, disappear from the Capitol City Air and Space Museum, eleven-year-old Amal Farah's father is blamed, and it is up to the four young friends to solve the mystery and save her father's job.