The Postal Inspections Unit is one of the oldest, least known and most dangerous areas of law enforcement in the country. These agents are no ordinary government workers; they carry badges and high-powered guns and deal with serial killers, bootleggers and con artists. They solved America's last stagecoach robbery, guard the transfer of the nation's gold reserve to Fort Knox, and captured the Unabomber. From snail mail to email, these agents literally put their lives on the line to protect us.