London 1812: For forty years Britain has dreamed of the Pacific island of Tahiti, a dark paradise of bloody cults and beautiful natives. Now, decades after the first voyage of Captain Cook, a new ship returns to London, crammed with botanical specimens and, it seems, the mysteries of Tahiti.

When, days after the Solander's arrival, some of its crew are found dead and their sea-chests ransacked - their throats slashed, faces frozen into terrible smiles - John Harriott, magistrate of the Thames river police, puts constable Charles Horton in charge of the investigation. But what connects the crewmen's dying dreams with the ambitions of the ship's principal backer, Sir Joseph Banks of the Royal Society? And how can Britain's new science possibly explain the strangeness of Tahiti's floral riches now growing at Kew?

Horton must employ his singular methods to uncover a chain of conspiracy stretching all the way back to the foot of the great dead volcano Tahiti Nui, beneath the hungry eyes of ancient gods.