Cassandra Khaw’s 2023 The Salt Grows Heavy is an upcoming secondary-universe horror fantasy novella.
A nameless ruler had a simple dream: capture and enslave what some might call a mermaid after murdering all of her sisters. The plan worked well enough, until the mermaid gave birth to her ravenous children.
Localized apocalypse ensues. The mermaid joins forces with a plague doctor, one of the few survivors of the domain. The two set out to find new lands to explore.
Note to readers: author Khaw frequently uses descriptors rather than names. Thus mermaid and doctor.