Think I read this in the 90s. May have been translated from French (or another language?) I think the book starts in America in modern times - late 20th century. A person's friend/partner/significant other(?) dies or is killed. The person, who I think is male, goes to a city in Europe, possibly Paris, to find out more. During his investigating, he talks to various people, goes into buildings, etc. One of these people is a nurse who eventually gets her throat slit, and he either sees it happen or finds the body. ***spoilers coming*** Some time after this, he sees the nurse, alive, on the street, and no longer a nurse. He goes back to some of the buildings where he had talked to people, only to discover that they are completely empty abandoned buildings. . . an entire scenario had been set up that didn't actually exist. He realizes that everyone he has talked to and all the places he has been were in fact people playing characters and places that were only set up to trick him into not solving this murder. I really thought this book was called either Facade or Charade, but the books I've found online with those titles are not this book. . . so maybe it's a one word title.