NEW YORK (AP).- 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. Now, would-be gumshoes must figure out what drove one of four suspects to kill him. Was it greed? Fame? Lust? Or revenge? That’s the plot of Murder at the Met, a murder-mystery scavenger hunt at the Metropolitan Museum of Art in New York run by Watson Adventures, a private company offering a series of such games at 27 museums in seven U.S. cities. On a recent Saturday, 40 people gathered in a basement room of the museum for