Fonts in Use explores the mystery of the typeface used on 1970s U.S. editions of Frank Herbert's Dune books. It's difficult to track down because it's a hand-made derivative of Davison Art Nouveau Modified, an already-rare cut of a typeface that could be licensed only from a single New York catalog and has never been professionally digitized.
The uncredited typographer worked with the Modified variant – at least that's what the A with curved bar and the E with curling middle bar shown in the limited typeface samples I've been able to compare suggest. The letterforms were used with varying degrees of condensation, something that was easily done with phototype. Given that Art Nouveau came with so many alternates, its use for Dune and beyond is impressively consistent. Across the dozens of applications, only a handful of variant glyphs were employed: see for example the two forms for A, one of them with a right stem that curves inward; the R with the curling terminal for "Trilogy" versus the one in "Frank Herbert" on the box set below; or the S with and without ball terminal at the top.
Orthodox Herbertarian is a painstaking recreation of it crafted in 2009 by MEP based on scans of the book covers—great for Dune fans, but lacking in features. Growing up in Britain, I got this look instead. My Dune!