When a Spanish priest learns of a skeptical organization's PR stunt to replicate the Shroud of Turin, Graham Eliot becomes part of his plan to counteract the bad publicity with a new revelation about the Shroud's authenticity. And the revelation relies on Graham secretly photographing the Shroud as well as the Sudarium of Oviedo—a relic believed to be a cloth wrapped around the head of Jesus as he died on the cross.

On the day Graham is to begin, the project is canceled without explanation, and a video of him calling the Shroud a fake and accusing the church of hiding something appears online. To defend his reputation, Graham must rely on the help of his eccentric translator as well as the skeptic who posted the video. But the alliance is shattered when a death occurs during the skeptic's annual convention in America—and Graham's graduate student is the one suspected of the murder.