Monique Roffey’s novel The Mermaid of Black Conch is set on a small Caribbean island where David works as a fisherman. One day, he sees a mermaid, huge and powerful, who is drawn to his guitar playing. David wonders if he has smoked too much spliff.

The Mermaid is a magical realist novel, which combines folklore and myth with the unfinished history of colonialism. The “shadowy ghosts” of slaughtered Caribs and kidnapped Africans bear witness to the atrocities of the past. The mermaid transforms back into the girl she once was, Aycayia of the ancient Taino people who were wiped out by disease and by a ‘murderer admiral’. She was cursed to become a mermaid, cast out and condemned to an eternity of loneliness.

The mermaid is not the only strong woman cursed by the past. Arcadia Rain is the descendent of plantation owners, abandoned by her lover and left alone in a decaying mansion to bring up her son. The love of her life cannot bring himself to live with her in a house built on a legacy of slavery. No one can escape the past, however distant or close.

The story explores the impact of disruptive outsiders on the small island community. The mermaid makes her appearance in 1976, when the world was exploding with the claims of women, gay people and black people for equal rights and new freedoms. And the novel draws on the demands of the marginalised for dignity and respect. The mermaid, seen as subhuman by the bigoted, teaches others how to be more human and share understanding across cultural barriers.

Humanity does not reside in the outward appearances of different, changing bodies or shared language. It exists within individuals simply because they are alive. This sense of a shared humanity is reflected in the structure of the book. The record of events is combined with David’s journal and poems, which give the mermaid her voice.

More disruptive than the mermaid is the brash, Trumpish American Thomas Clayson and his son Hank who arrive at Black Conch on a fishing trip. Thomas is haunted by his own failures as a businessman and a father. He feels nothing but contempt for his poetry-loving son.

Clayson likes to hunt, to stuff the heads of animals he has killed and mount them on his walls. Of course, Clayson is not the first white man to exploit natural resources of the island. For hundreds of years, white men arrived at Black Conch to pursue their inflated ambitions. Each successive wave of invaders left their mark on the island, their tools, their buildings, their crops. While Clayson sees the world through the prism of dollar signs, Aycayia sees meaning in everything that lives.

Characters are defined by their relationship with nature, with the sea, with animals and sea creatures. Like the past, the seas, the hurricanes, the rains are all stronger and more enduring than human ambitions. The sea advises, “Be careful what you ask, take only what you need.” Aycayia remarks on how, “The kingdom of the sea is dying. Filled up with plastic.”

Aycayia stands for all the creatures which have been caught, stolen, abused and destroyed for profit. In this image of the mermaid, Roffey is continuing an idea expressed in a poem by Pablo Neruda. His mermaid is a metaphor for a natural world which is being destroyed by human greed and arrogance.

Roffey also references a tradition of Caribbean literature. Arcadia Rain is reading Derek Walcott’s 1962 collection of poetry, In a Green Night. Trinidadian Roffey expected her Caribbean novel to “live its life at the margins”, but it has won the lucrative Costa Book Award.

So, mermaids do change lives. Life in Black Conch is enriched for those who see beneath physical difference to a shared humanity. David writes in his journal, “That mermaid be a revolutionary.” And in a gentle, magical and lyrical way, she is.

Judy Cox is a teacher in East London. She is studying for a PhD in women and the Chartist movement at Leeds University. She is the author of The Women’s Revolution: Russia 1905-1917 (Haymarket, 2019) and Rebellious Daughters of History (Redwords, 2020).