By day, he taught spycraft at the CIA's clandestine training center, The Farm. By night, he was a minivan-driving single father racing home to have dinner with his kids. But for more than two years, Jim Nicholson met covertly with agents of Russia's foreign intelligence service and turned over troves of classified documents. In 1997 Nicholson became the highest ranking CIA officer ever convicted of espionage. But while behind the bars of a federal prison, he groomed the one person he trusted most to serve as his stand-in: his youngest son, Nathan.