When Cardinal Lawrence is tasked with leading one of the world's most secretive and ancient events, selecting a new Pope, he finds himself at the center of a conspiracy that could shake the very foundation of the Catholic Church.

A westerner named Casey, studying Ninjutsu in Japan, is asked by the Sensei to return to New York to protect the legendary Yoroi Bitsu, an armored chest that contains the weapons of the last Koga Ninja.