[1][2] Special Agent Aloysius Pendergast is approached by Percival Lake, a sculptor who wishes to hire him as a private investigator.

Lured by the promise of a rare bottle of wine as payment, Pendergast and his ward Constance Greene accept the job.

An analysis of the bone reveals that it dates back to the 1840s and Pendergast concludes that it belongs to the captain of the Pembroke Castle, a ship that disappeared without a trace off the coast of Exmouth.

By retracing McCool's work, Pendergast learns that the Pembroke Castle was carrying twenty-one flawless rubies known as the "Pride of Africa".

In their desperation, the whalers extinguished the lighthouse and lit a bonfire to lead the Pembroke Castle to run aground in the hopes of looting it.

The monster wreaking havoc in Exmouth is Morax, a man with a genetic mutation whose monstrous appearance is the product of selective breeding by the coven.

Constance is met by Bradley Gavin, the Exmouth deputy chief of police, who reveals that a large portion of the town were part of the coven.

Pendergast realises that while the murders of McCool and Dunwoody threw the coven into crisis as it risked their exposure, releasing Morax was not part of the plan; someone else is responsible.