Showing The Emperor's Tomb by Steve Berry

Hearing that his old friend Cassiopeia Vitt is in trouble, Malone follows the few clues he has and realises that they are in the middle of something huge, involving Russian and US oil interests and a centuries-old secret. After stumbling across two dead bodies and into the crosshairs of his former boss, Malone finds himself in a race to unravel the mystery of an emperor's tomb, a sinister society, and a deadly battle between two ruthless men for supremacy in China - and the world.