| The Black Circle | |
 | |
| Author | Patrick Carman |
| Main Setting(s) | Cairo, Egypt; Various locations throughout Russia |
| Publication date | August 11, 2009 |
| Pages | 178 |
| Series | 39 Clues |
| Preceded by Beyond the Grave |
Followed by In Too Deep |
Summary[]
A Game of Cat and Mouse
"A strange telegram lures fourteen-year-old Amy Cahill and her younger brother, Dan, deep into Russia and away from the only trustworthy adult they know. Signed with the initials NRR, the telegram launches a race to uncover a treasure stolen by the Nazis and the truth behind the murder of the last Russian royal family. All too soon, the treasure hunt starts to smell like a Lucian trap. But the bait might just be irresistible...what will Amy and Dan risk to find out what really happened on the night their parents died?"