Last summer, the Royal New Zealand Navy ventured far from its beaten path into the iceberg-strewn waters off East Antarctica. There it found three pirate ships illegally fishing Antarctic toothfish—a deep-dwelling favourite of top chefs, a fishery worth nearly $600 million. What followed was a four-month chase also involving Australian authorities and two vessels of the direct-action organisation Sea Shepherd. By the end, five pirate ships were detained and one lay at the bottom of the sea, sunk in suspicious circumstances. This is a story of navies and pirates, of governments and vigilantes, of an ugly fish that grows to the size of a human, and a daring pursuit across three oceans to drive poachers out of our seas.