In a time when several terrifying species of beasts roamed the seas, monster hunters were celebrated and labeled as true heroes. Of all these atypical heroes, none is more beloved and better known than the great Jacob Holland. But when the young Maisie Brumble appears out of nowhere and sets off with her ship, he chooses a completely unexpected ally. Together, the two embark on an epic journey on some waters still unexplored until then and will make history.