Youngest of five sisters, and now 15, mermaid Muirgen—or Gaia, as her mother wished to name her—can now visit the ocean's surface.Her life has been dominated by her (one-dimensional) tyrannical Sea King father, who is only interested in her obedience and beauty—a point the author makes excessively—and with wondering why her mother left. Gaia rescues a young man named Oliver from a shipwreck and is promptly smitten. Back underwater, she makes a deal with the Sea Witch (the most nuanced and engaging of the characters) to have her tongue cut out in exchange for legs so she can be with him. Gaia has one month in Oliver's world to make him love her or else she dies. It's a long month for readers. Tedious descriptions of Gaia's bloody, broken feet (metaphor alert for standing on one's own feet) and Gaia's attempts to attract Oliver with her compliant passivity (all the while making astute observations of what is expected of females) repeat tirelessly. Eventually Gaia has her ostensible empowerment moment, but whether or not Gaia lives to please men, her identity is still controlled and defined by them, and readers may wonder whether that is actually empowerment at all. All mermaids are white, Oliver is dark-skinned, and other human characters are ethnically diverse.This heavy-handed attempt to update a fairy tale pits trope-infused female characters against trope-infused male characters to the disenfranchisement of both. (Fantasy. 14-18)