The Course of the Heart, by M. John Harrison

I've just finished this extraordinary, and extraordinarily strange, book. And it leaves its mark. The story is sparked by a mysterious ritual, never fully described, enacted by four university friends. In later life, the results of this invocation haunt them all - except, it seems, for the narrator, who spends a lot of his time trying to help the others, or at least to comfort them.

If you don't know much about Gnostic religion and the 'Pleroma' (I didn't), it's worth having a dictionary handy. But don't let me put you off: if you invest a little time in this book, it repays your trouble many times over. Even if you simply let it wash over you, Harrison's vision is remarkable and genuinely unique. The writing is pin-sharp and often astonishingly beautiful. I can safely say you won't have read a book quite like it. (Except perhaps for another Harrison: check out short stories of a similar ilk in The Ice Monkey.)

Click the cover to buy The Course of the Heart from Amazon.co.uk