Mary Firth is a Stormsinger: a woman whose voice can still hurricanes and shatter armadas. Mistaken for a brutal pirate, facing execution, she is forced to join forces with pirates and bounty hunters. Faced with servitude to a pirate lord, Mary offers her skills to his arch-rival in exchange for protection - and, more importantly, his help in sending the pirate to a watery grave.

In this world of warring fleets and winter seas hums with bound magic. As Mary charts a course to revenge, and survival, her dreams are haunted by spectral creatures and strange voices. She must sail into the eternal ice at the limits of the world, and break through to the hidden worlds behind, as she discovers that forces older and more powerful than pirates would make her a slave.