• 08.005 It then became pitch-dark –
• 08.005 not what you call pitch-dark,

This word appears in only one paragraph in the whole book… twice.  And Chapter 8 is famous for not having many hyphenated words.  The word has its own OED  sub-entry with and without hyphens in the examples.

“pitch, n.1.” OED Online, Oxford University Press, June 2017, http://www.oed.com/view/Entry/144680. Accessed 19 September 2017.