Carman, Patrick. <br/><br/>
The 39 clues:  The black circle / 
Patrick Carman 
 - New York :  Bantam Books,  c2012 
 - 168 pages :  illustrations ;  20 cm. 
<br/><br/> 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 about 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? 
<br/><br/><label>ISBN: </label>9781407135649 
<br/><br/><label>Subjects--Topical Terms: </label><br/>FAMILIES -- HISTORY -- FICTION
<br/><br/><label>LC Class. No.: </label>FIC .C37 2012