The oceans are some of the last untamed frontiers on our planet.
Too big to police, and under no clear international authority, these treacherous waters play host to the extremes of human behaviour and activity.
From pirates and vigilante conservationists to stowaways and seabound abortion providers, Ian Urbina introduces us to the inhabitants of this hidden world and their risk-fraught lives, and exposes a global network of crime and exploitation to which all of us are connected.