In new year's day 1923, the Mauldrey Exhibition of mesoamerican sculptures opens to the public. Many illustrious guests attend the opening ceremony and have a chance to introduce themselves. 

Sir Clarendon, Mudiwa and John White get introduced to professor Julius Arthur Smith, a fellow member of the Oriental Club. Professor Alan Hart, a university colleague of Dr. Smith is also attending, as is the young priest Oscar Danjou from Paris, having recently arrived in London. 

David McCullen, Mr. White and Mudiwa meet for the first time, in a mutual visit to the Kerguelen archipelago in the Southern Indian Ocean.

In that remote corner of the world, they come in contact with a murderous cult of worshippers of the God of the Black Stone, an otherworldy entity put to torpor at the depths of prehistory and only reawakened two centuries ago. A meeting with a german occult society expedition informs them of the terrible truth of the God's cycle of awakening, demanding a sacrifice every thirty years to ritually bind the being back to slumber.