Return of the Dark Queen (Book 6)

Can you keep a secret? By day, Molly Holmes is just like any other little girl, but by night, she becomes the secret mermaid in this magical series. Far out in the ocean live the Shell-Keeper mermaids. While the rest of the world sleeps, one little girl joins them for some magical mermaid adventures. Disaster has struck - the Dark Queen has captured the last piece of the magical conch shell! Unless Molly and the Shell-Keepers can stop her, she will seize control of the ocean, and cast her wicked spell over all the undersea creatures...