For thousands of years we guarded it. But now it has been found. This could be the end – for us; for our organisation; for the world. You must destroy it, and those who have taken it.

An ancient object is discovered in a Cairo souk. Hours later, the market trader who sold it is tortured to death. As the bodies begin to pile up, a request for help is sent to British Museum historian Angela Lewis. 

Angela travels to Spain with her ex-husband, undercover police officer Chris Bronson. There they discover the key to the greatest secret in the history of Christianity. 

Their only problem is deciphering it before they are brutally murdered like those before them...