One of many obscure points in the story involves a discussion between Dr Abell and a clergyman over some rather strange entities:
he would ask me, for example, what place I believed those beings now to hold in the scheme of creation which by some are thought neither to have stood fast when the rebel angels fell, nor to have joined with them to the full pitch of their transgression.Now when I first read this (many years ago, in pre-internet days) I immediately thought 'neutral angels'. I had at the time, however, no clue as where the term had come from. In listening to the podcast I was reminded of that odd phrase and decided that the amazing Google machine might be of assistance. Sure enough, it took me to some notes on Dante, who placed the supposed neutral angels in the vestibule of Hell. Apparently several mediaeval legends mention such beings.
Conventionally, and in a lot of bad horror movies, 'black magic' is performed by the intercession of demons. You sell your soul to Satan ('Sign in blood on the dotted line, please') and you get to see your enemies destroyed while you win the lottery, gain promotion, grow an inch taller, pull all the best birds etcetera. But it seems that Dr Abell was of the opinion that one could recruit 'non union' fallen angels to achieve similar results, without having to sell his soul.
A brilliant plan. What could possibly go wrong?