On his Twitter feed today Robert Macfarlane revealed the cover for Underland, “which explores the lost worlds that lie beneath our feet” and is due to be published next May. It is, he says, “the longest, strangest, deepest, darkest book I’ve ever written – and probably ever will write”. In a piece on his publisher’s website, he writes about working on the cover with the artist Stanley Donwood.

  When I interviewed Macfarlane in 2015, he told me the book had taken him to unfamiliar places not just underground but on the page, and was prompting “new challenges of form and new forms of language”.