It's taken me years to realize it, but this story is set within Sierra Leone! Some of you may recall I visited Sierra Leone in April, 2012 and consequently, I have a better idea now of what Wells was trying to establish in this story. I don't know if Wells ever visited Sierra Leone, however. If you'd like to read an authentic account of mysticism in Sierra Leone, I recommend Tim Butcher's Chasing the Devil: the Search for Africa's Fighting Spirit (Chatto & Windus, 2010).
You can download a copy of this radio show from archive.org here.