It was supposed to be a few days of fun...Nineteen-year-old Song Mart nez moves between two worlds: an average American college student in a quiet seaside town and an undocumented immigrant on the path to citizenship. The uneasy balance between these worlds creates a life of routine, one where Song tries to stay invisible and not make waves.Until a witch proposes an offer Song can't refuse: her voice for a tail. A chance to leave her worries on land for a few carefree days under the sea as a mermaid. When Song agrees, she finds herself in the middle of a rivalry that has spanned hundreds of years.Whatever Song does next, it could not just change the lives of an underwater kingdom. It could also endanger her life.