Deep blue /
Jennifer Donnelly.
- First edition.
- New York : Scholastic , c2015.
- 340 pages ; 22 cm.
- Waterfire saga ; book 1. .
Maps on endpapers.
Uncovering an ancient evil, Serafina, a mermaid of the Mediterranean Sea, searches for five other mermaid heroines who are scattered across the six seas, to save their hidden world.