The vivid and unforgettable nightmare sequence in Vertigo was actually developed quite early in the production process. It is described in detail as early as Alec Coppel’s draft of the script. Hitchcock enlisted Modern artist John Ferren to storyboard the sequence, which was followed faithfully in filming. Ferren’s credit in the film is an ambiguous “Special Sequence By.”
Alfred Hitchcock’s Vertigo (1958).