During the last two years of her life, Princess Diana (Naomi Watts) campaigns against the use of land mines and has a secret love affair with a Pakistani heart surgeon (Naveen Andrews).

Mysterious cell phone messages promise a young American engineer untold wealth – then make him the target of a deadly international plot. Dangerous security operatives chase the engineer across the globe, while a powerful government official pursues a mysterious agenda that threatens the stability of the entire world.