The world’s top art sleuth, Robert Wittman, built a twenty-year career that was nothing short of extraordinary. He went undercover—usually unarmed—to catch art thieves, scammers, and black-market traders around the world, rescuing some of history’s greatest treasures. By the FBI’s accounting, these high-stakes gambits saved hundreds of millions of dollars’ worth of masterpieces and rare historic artifacts. Wittman says the statistics aren’t important. Which is worth more—a Rembrandt self-portrait or an American flag carried into battle? They’re both priceless.