Berry studies accusations of poisoning across the slave societies of the Atlantic, assembling a body of more than five hundred cases from Bahia, the Dutch Guianas, Virginia and Martinique and reading them alongside one another rather than colony by colony. The comparison brings out what no single archive shows: statutes written under very different regimes, and the prosecutions mounted under them, rose and subsided along strikingly similar curves through the eighteenth and early nineteenth centuries.

An opening chapter uses reconstructed African root words together with European philology to follow how notions of poison, healing and sorcery shifted on both sides of the ocean before people carried them west. The remaining chapters change vantage point in turn: slaveholders and officials, who read poisoning as a seizure of their authority; the enslaved, who sought out healers of African descent and sometimes set investigations against those same healers in motion; and the practitioners themselves, valued and feared for what they knew.