It is Victorian 1880 in London, and the time of the Great Game when Britain and Russia struggled over control over Afghanistan, when the series’ heroes need to catch a supernatural opponent. Soon, their enemy – the adventurous Russian Czarina – joins their force, because the Czar and the Empress both are in danger of taken over by the Afghan wizard.

When a private envoy of the queen and member of Lord Carmichael's discreet service goes missing, Balfour and Meriwether are asked to look into the affair. They will find a labyrinth of dreams, horrors risen from hell, prophecy, sexual perversion, and an abandoned farmhouse on the moors outside Harrowmoor Sanitarium. The earth itself will bare its secrets and the Empire itself will tremble in the face of the hidden dangers they discover, but the greatest peril is the one they have brought with them.