Vertigo (Universal Legacy Series) is my favorite Hitchcock film, and one of my favorite films, period. I watched it again recently, and I was interested to see how the film adaptation compared to the original. So I looked on Amazon and found a used copy of a British edition of the novel, and it's fascinating.
French writers Thomas Narcejac and Pierre Boileau wrote several mysteries together back in the 1950s, and two of them became famous movies, DIABOLIQUE and VERTIGO. They specialized in twisty plots and surprise endings, with morally ambiguous characters and lots of mood and atmosphere. The original novel of VERTIGO, D'ENTRE LES MORTES (From Among the Dead), is set in Paris, not San Francisco, and the surprise ending is quite different from Hitchcock's. It's actually a better ending, but the film censors in the '50s would never have allowed Hitchcock to use it. It's interesting to note all the ways the original and the film compare and contrast. If you're a Hitchcock fan like me, find a copy of the novel and see for yourself. It's excellent.