Book details
The Black Circle
The 39 Clues, 2009 by Patrick Carman
on Goodreads (51,931)
Description
The Black Circle is the fifth installment in the 39 Clues series, where siblings Amy and Dan Cahill continue their worldwide quest to discover the secrets of their family's power. This time, they find themselves in Russia, where they must outsmart their rivals and navigate the dangerous underworld of the Russian black market.