'Your papers, please' must never be heard in America

An assistant museum curator who questioned the authenticity of a Leonardo da Vinci has been killed. Before he died, he left a code in his appointment calendar and a cryptic trail of clues connected to secrets in works of art that point to the killer.
An assistant museum curator who questioned the authenticity of a Leonardo da Vinci has been murdered _ but before he died he left a code in his appointment calendar and a cryptic trail of clues connected to secrets in works of art that point to the killer.