From the award-winning author of The Great Trouble comes a story of espionage, survival, and friendship during World War II

Bertie Bradshaw never set out to become a spy. He never imagined traipsing around war-torn London, solving ciphers, practicing surveillance, and searching for a traitor to the Allied forces. He certainly never expected that a strong-willed American girl named Eleanor would play Watson to his Holmes (or Holmes to his Watson, depending on who you ask).

But when a young woman goes missing, leaving behind a coded notebook, Bertie is determined to solve the mystery. With the help of Eleanor and his friend David, a Jewish refugee--and, of course, his trusty pup, Little Roo--Bertie must decipher the notebook in time to stop a double agent from spilling the biggest secret of all to the Nazis.