They were three best friends at Harvard Law School who turned their backs on lucrative careers to follow an exceedingly rare path: Michael Weston, who jogged through Harvard Yard in combat boots and openly scorned corporate life, joined the Marines. Helge Boes and his girlfriend Cynthia Tidler, who shared their friend’s sense of duty and adventure, joined the CIA. Their choices - made out of passion, patriotism, and an urge to live an unconventional life - intertwined their fates. Boes, a covert CIA operative, died when a grenade went off during training in Afghanistan in 2003, leaving Tidler, whom he...