In the age of Donald Trump, it's important to separate fact from fiction about anything and everything. In a new book, Gary Vikan, former director of the Walters Art Museum in Baltimore, unravels the mystery of the Shroud of Turin, the supposed burial cloth of Christ. Having studied the shroud for more than three decades, Vikan calls it a brilliant hoax, not a miracle but a mysterious work of art that showed up in France in the Middle Ages during the great plague.