The Tyrants of Kool-Sim seems to be the most outrageous work of Cobban's and is a sequel to a seemingly pure adventure novel with no supernatural or fantastical trimmings called "The White Kaid". It deals with a rescue operation of notorious adventurer Tom Malleson by his sister and her friends. Though the book starts out written in a rather simplistic way and focuses on a pair of schoolboys trying to mount their own, hopelessly naive expedition to save Tom Malleson, after a chapter or two the two boys mostly retreat backwards to the status of background characters and the principal focus is directed elsewhere. I'm not sure if it's a coincidence or if Cobban decided to abandon his primary focus on the boys as main leads as he wrote, but one does notice an increase in the quality of writing once the attention is focused on adult characters.
The leader of these, Captain Betterton, follows the trail of Tom Malleson to Algeria and discovers him in an almost inaccessible country whose only entrance is a deadly gorge full of poisonous flowers, a land populated by pygmies, called Kool-Sim. There Tom has been relegated to playing the role of a statue of the Sun God.
All is well and good until the party meet the aristocracy and King, the jewish features of which are noted by Betterton, along with their love of counting, lacking any culture and having acquired control of the land via loans. Worse these Jews inbred with the local pygmies have blood that is so toxic it literally became lethal poison.
The implications are not in any way outweighed when Betterton says:
" They are Jews, of course ; and, like Jews everywhere, they come to trade and stay to rule."
Later still, after the local arabs and pygmies have managed to overthrow the King they replace him with Abdallah, the son of the only man to have previously escaped the land of Kool-Sim. Tom Malleson then tells Abdallah to exterminate every last one of the nobles related to the King he can find, because "however humble to begin with, they will arise again, with as much destructive power as ever. It is the way of all their kind. Therefore spare them not, wherever thou findest them."
Oh and when they English party run into the survivors of the court who try and kill them with poison darts, they drown them in the lake like rats.
Finally, the image of the King on the title doesn't bode well in hindsight either.
It's rather a shame that Cobban had to basically marinade the text in racist overtones because as an adventure novel dealing with the fantastic, it's actually fairly well written and readable.