American investment banker Ben Hartman - son of legendary Max Hartman, who built a financial empire up from next to nothing - is on holiday in Switzerland when he meets one of his oldest childhood friends - who promptly tries to murder him. Hartman has no choice but to kill his attacker in his self-defence. He barely survives the ordeal.
From the other side of the world, Anna Navarro, a US government agent, is sent to surreptitiously look into a string of deaths of old men in Europe. The only thing the victims have in common is some old OSS file, code named SIGMA. But as she starts to make progress, she is dragged off the case and declared rogue. Someone wants a secret kept and the futures of Hartman and Navarro become entwined, and as they get deeper and deeper into trouble, it becomes obvious that there is more at stake than they could have ever imagined……..
