Borderless delves into the Caribbean and world view of the surprisingly egalitarian life on the sea and the story of gender defying pirate leaders of the day, focusing on the relationship between Anne Bonny (Bonn) and Mary Reed (Mark). The opera revolves around the meeting of Anne/Bonn and Mary/Mark and their attraction to each other as male presenting pirates. It follows their discovery of each other being the female sex, and their expressions of freedom in their gender fluidity, their love for each other and the development of their polyamorous relationship with Calico Jack.