As the twentieth century dawns, Holmes and Watson hear a knock on the door. Their enigmatic guest is Abdul Faziel, an Arab man from the mysterious land of Marrafaze - a land only rumoured to exist.
Son of the Sheik, Faziel is fleeing his homeland to seek help. His father has been turned against him by the connivance of his brother, Mustapha, and the Grand Wazir. Mustapha wishes to usurp the throne and dispose of anyone who gets in his way.
The plot thickens when Sherlock visits his brother Mycroft. Mycroft insists that Sherlock journey to Marrafaze in order to make diplomatic contact with the Sheikdom, over the fate of a certain mineral that has been discovered there - a mineral that could be manipulated for warfare, and disastrous if in the wrong hands.
But there is no map to Marrafaze, and Holmes and Watson must embark upon an arduous trek across the Sahara desert, voyaging through uncharted territory.
Battling alone through the blistering heat, with food and water in short supply, it seems they'll never be able to navigate a way out of the barren wilderness.
When they finally make it to Marrafaze, 'the end of the world', they encounter a land ruled by religious superstition and the whims of the Grand Wazir. Isolated in strange and incomprehensible territory, Holmes and Watson find themselves in unimaginable danger.