Is it a Tench?

Two real-time reviews (among several others over the years) strongly connected with this increasingly preternatural, hawling-relevant question from John Cowper Powys in his ‘The Glastonbury Romance’ (1933):

The Rift by Nina Allan

Rule Dementia! by Quentin S. Crisp

This subject deserves a googling galore.

Other quotes of mine from that Powys book:

(Painting by Ade Hodges)

Edit: more in comments below –