This is Book Four in the Margaret of Greenwich? series.
Margaret searches in Tokyo for Maureen's kidnapped son. He is believed to live with Erich, the Russian Mafia leader who raped her, and Olga, his murderous wife.
“Remember that you're just an ordinary teenager on a cultural trip,” Margaret is instructed.
While working as the child's babysitter, Margaret learns of Erich's counterfeiting activities. Every spy who sought this information was brutally tortured and murdered and Margaret fears that she will meet their fate.
But Margaret has allies too: Vladimir, a former general in Russia's Presidential Security Service; Peter and “Joe,” American and Japanese intelligence officials; Ulrika, Margaret's firearms instructor; and fourteen-year-old Randy who is the love of her life.