“Guardian of the Depths is a thrilling fantasy adventure with an unforgettable heroine at its helm. Tilly Hornsby brings Kaia Jones to life with remarkable depth, charting her transformation from solitary marine biologist to fierce protector of an ancient legacy. The all-female crew of the Neptune’s Dagger adds an exhilarating twist, while vivid prose paints everything from Scotland’s moon-shaped coves to storm-lashed pirate battles in cinematic detail. Rich with magic, danger, and heart, this series opener leaves readers eager for the next voyage.”