When Arcadia Jones, a Harvard professor and curator of the Metropolitan Museum in New York City receives a scrap of what appears to be an old manuscript, she has it carbon dated and confirms that it is from the 1500's During research, her hunch suggests that the sample is from one of da Vinci's lost books that were stolen from his protégé, after his death. There is no accompanying letter, only a return address, so her only course of action is to travel to Rome and contact the sender, who corroborates her intuition, and tells her that there are eighty books full of notes and diagrams of his inventions which were discovered at the Roman Baths in England. She estimates their worth at millions of pounds, but he informs Arcadia that they were stolen from him - except one page. A clue suggests that a local bar patron may be the culprit, which leads her to Geneva and puts her hot on his tail and a separate thief and murderer who leads her to Panama. Will she be able to find the murderer and get back the manuscripts?