Ben Hartman is on holiday in Switzerland when he meetsone of his oldest childhood friends --who promptly tries to murder himHartman has no choice but to kill his attacker in self-defence,that the body and all evidence of the fight have disappeared,Anna Navarro,a US government agent,is sent to look into astring of deaths in Europe.The only thing the victims have in common isan old OSS flle, codenamed SIGMA But as she starts to make progress,she is dragged off the case, attacked and deciared rogue.