This 1970s horror novel, in common with a lot of books of the period, is short so at least the story is not drawn out. The basic idea is that the Arabian Nights tale of Ali Baba and the 40 thieves is a sanitised version of a horrific reality in which Ali Baba was a powerful practitioner of black magic who would stop at nothing for political advantage and who engaged the most powerful djinn (spirit) to achieve his goal. The djinn itself is the Forty Thieves which were really forty forms into which it could transform itself to deliver ghastly forms of death to Baba's enemies. To obtain the djinn he agreed to an appalling bargain where he turned over a young girl to an evil sect.

In contemporary (70s) America, the protagonist, Harry, attends the funeral of his godfather and soon realises all is not well with his godfather, Max. He learns that Max, a keen student of Arabian artefacts, myths and magic, became obsessed with a tall jar decorated with poppies and eyeless horses, to the point where he secured it in a tower room and removed all portrayals of faces from the house including pictures in the paper and even a carving on his favourite pipe. This obsession led to the tragedy of his death, a rather nasty one.

At the funeral, Harry meets Anna and they 'hit it off' and begin a joint investigation. Anna knows a lot about Arabic culture and even obscure dialects, and later the reason for that is revealed - which I found implausible.

The story starts off nicely creepy and builds. However, the prologue and also the later development of the story consist of truly horrifying forms of sexual assault on women so I would red flag that as a content warning. For that reason, my initial assessment of between 3 to 4 stars dropped drastically and I can now only rate this as 2 stars. ( )

Harry Erskine is the much more appealing and better written Harry Dresden.

Another of Masterton's early horror books. It was a good, fast read but not one of his better ones. Readable but not a must read.

Back Cover Blurb:
It began with a curious investigation of an ancient Arabian jar and the strange legends of sorcery it symbolised. Then legend and logic demand that the jar be opened - the secret of the djinn must be exposed to the light of reality. ( )