When Marco Polo left China, he had 14 ships laden with gold, treasures and more than 600 passengers and crew onboard. When he finally made his home port, only one ship remained with 18 passengers. So what happened to those other ships? The Cintamani Stone (purported to be a fabled jewel that grants the owner great power) is one part of the story, the other is the path that leads to Shambhala: the fabled lost city. Only one man is up to the task of solving this ancient mystery: Nathan Drake.