After reading many of James Hadley Chase's books, I can say that he certainly believed in the world of the supernatural, voodoo; Juju as we like to say in Africa. As a western man, Chase would ensure that the main protagonists in his work pooh pooh the idea of let's say Voodoo, but the average reader would in the end have no doubt that the supernatural exists after reading the pertinent books!
Such is the case here, where we are introduced to the concept of the zombie (In Africa the illustrious singer, FELA actually had a best selling song titled zombie anyway...). No matter, here as an African I am very impressed with the character of Gilroy, the coloured pianist or pianist. A dignified, quiet character, he is certainly into "voodoo" himself! Gilroy it is who knows when Doc Martin is killed, and where he is killed. More importantly, Gilroy is the one, in stunning fashion (using "primitive" drums) who somehow beckons to the young lady, Susan to "sleepwalk" and lead the odious Rollo to where the all-important corpse is hidden.
Another intriguing, "coloured " character in this book is Celie, the very attractive mistress of Rollo. (She does not belong exclusively to Rollo, but that is neither here nor there). Butch - a ruthless killer - is another colourful, though cruel character in the book. No wonder young Joe and Susan (the real "heroes " in this book) are in mortal dread of him. Butch, true to his reputation is responsible for most of the violent deaths in this book, and it seems something of a pity that in the end, he is "only" arrested by the police...