In late 2001, FBI Special Agent Steven Carr received a coded letter in which an alleged CIA analyst with top secret clearance was offering to sell information about U.S. reconnaissance satellites, air defense systems, weapons depots, munitions factories, and underground bunkers throughout the Middle East. Rooting out the traitor would not be easy, but Carr and his team spent years hunting down a dangerous spy and his cache of stolen secrets. In this fast-paced true-life spy thriller, Yudhijit Bhattacharjee reveals how the FBI unraveled Brian Regan's strange (and dyslexic) web of codes to build a case against a man who nearly collapsed America's military security.