Mildly entertaining, lightweight hokum. A tubby barman self-dramatises by donning a leather coat, matching fedora and an odd slangy patois (half mockney-half Sam Spade) and takes us into a world of silly make-believe and faux paranormal investigation. He drinks a lot; claims to see off demonic entities, water pixies ('undines') and other revenants with the help of his toy pistol ('Zozo gun'), streetwise 'tude ("the night of the exorcism, I kicked some serious ass" etc.) and coterie of odd mates (eg: 'Nick the Witch'); and generally indulges his fantasy of being an amalgam of Aleister Crowley, Bruce Willis and Gandalf.
It's daft beyond belief, but not without its charm. For all his self-regarding silliness, the author seems quite a nice chap and I wish him well with this book's sales!