An American art appraiser, Patrick Donovan, is sent to Venice to evaluate three paintings belonging to the famous Galleria dell'Accademia. The company that insures the paintings has hired Donovan's employer, the International Center for Art Authentication, to verify that two Bellini canvases as well as the crown jewel of the museum's collection - Giorgione's 'La Tempesta' - are originals. Donovan contacts Allart van Beuningen, the director of the Accademia Museum, examines the two Bellinis and confirms that they are authentic. But before he can check 'La Tempesta', with floodwaters rising and the Galleria closed to the public, the painting is stolen by assailants who attack Donovan and Van Beuningen's beautiful adopted daughter, Chiara, a professional art restorer who works at the Museum. When the painting gets stolen, Donovan has to turn into a detective in order to try to track down the thief and recover the canvas. Soon Donovan's investigations reveal a sophisticated forgery ...