The Black Circle (The 39 Clues, Book 5)

In the fifth installment of the bestselling The 39 Clues series, fourteen-year-old Amy Cahill and her younger brother, Dan, are drawn into a thrilling treasure hunt in Russia after receiving a mysterious telegram signed NRR. This adventure leads them to seek out a treasure stolen by the Nazis and unravel the secrets surrounding the murder of the last Russian royal family. As they navigate the dangers, they must also confront the possibility of a Lucian trap and grapple with what they are willing to risk to uncover the truth about their parents' deaths.