American investment banker Ben Hartman, son of legendary financial entrepreneur Max Hartman, is on holiday in Switzerland where he meets a childhood friend, who promptly tries to kill him. Narrowly surviving, Ben discovers that all evidence of the confrontation has disappeared.
Meanwhile, Anna Navarro, a US government agent, is looking into a string of deaths around the world. The only thing linking the victims is an old OSS file, code-named SIGMA. But as soon as she starts to get somewhere, she is dragged off the case and declared rogue.
Someone wants this secret kept and the futures of Hartman, Navarro and the entire world are at stake.