This book is about a mermaid named Cora who wants to be in the most popular swim team in the sea- The Singing Sirens. Since she failed her spelling test, the coach says she can't join until she gets an A on the next one, or else her spot will go to a obnoxious mermaid named Vivian Shimmermore. Her sistes are celebraties ! Her mom gifts her a diary and Cora thinks she is under a "spell"! But all she really needs is to learn how to spell! Will Cora be able to pass her spelling test, become a Singing Siren, and stay true to herself al at the same time???