It鈥檚 now 40 years since The Exorcist hit the big screen and was promptly banned by local authorities all over the UK because of its graphic scenes of demonic possession.
It was terrifying stuff and, where it did get shown, there were reports of people passing out in the cinemas or rushing outside to throw up.
But for William Peter Blatty, who adapted his own bestselling novel for the screen, both the book and the film carried an important religious message. Blatty was - and presumably still is - a Roman Catholic and the novel was based on the true story of a child apparently delivered by a Catholic priest from what looked very much like the grip of an evil entity.
Blatty鈥檚 point is that the existence of extreme supernatural evil is strong evidence for existence of a spiritual force for good.聽
Not surprisingly, the success of The Exorcist led to an explosion of demonic novels and movies about the coming of the Antichrist which, as spin-offs tend to, got less and less credible before finally fading into the ether.聽
For a long time afterwards nobody would go near big supernatural themes. Meanwhile, western society changed and became increasingly secular. The new gurus were atheists like Richard Dawkins, with undisguised scorn for the church, the chapel and the mosque. Priests had their backs to the wall.
But what if somebody decided to hit back? What if the power of an unsympathetic Old Testament God was unleashed again?
Thriller-writer Philip Kerr decided it was time for a radical variation on The Exorcist. On this weekend鈥檚 , he discusses his novel Prayer in which several prominent atheists are mysteriously struck down.
Kerr, who grew up in a contricting Christian non-comformist atmosphere in Scotland, is essentially a non-believer. But we also talk to the author of another novel dealing with evil spirits against the background of a culture where exorcism is commonplace.
Certainly not what you鈥檇 expect from GF Newman, creator of TV鈥檚 Judge John Deed and other novels and screenplays that deal with bent cops and corrupt authority.
Gordon Newman is also famous for his veganism and ecological campaigning.聽 His views are shared by Martin Shaw, who played Judge Deed, and production crews working on the series would be offered meat-free alternatives to the usual bacon butties. His house in the Wye Valley near Tintern employs various forms of alternative technology.
It鈥檚 no surprise to see the Catholic Church getting a bashing in Newman鈥檚 new novel, Dark Heart, but you might be interested to hear his views on the validity of exorcism.
What鈥檚 also interesting is that, in the interests of saving trees, Dark Heart is a novel which has only a virtual existence, released directly into the ebook format and highlighting another publishing revolution.聽
Until quite recently, ebook only publications tended to be first-time novels rejected by publishers for reasons which were all too obvious. But now established bestselling writers are successfully e-publishing shorter stories which publishers might see as too much of a financial risk.
It also, of course, means that established authors can sell to thousands of regular readers without publishers and booksellers pocketing most of the profits.
Dark Heart, however, is one of the first full-length novels from a major writer to appear only in ebook format. Is this the start of something truly radical? We鈥檒l be keeping an eye on it.
Listen to on 成人论坛 Radio Wales on Saturday 28 December from 1.30pm. 聽