Transformed by the goddess Yemoja into a Mami Wati, an African mermaid charged with collecting the souls of those who die at sea, Simi goes against the gods to save a living boy, Kola, from drowning.

Seventeen-year-old Lily, half-mermaid and half-human, has been living on land and attending high school, where she develops a crush on a boy but is afraid to tell him of her true destiny as the ruler of the undersea kingdom of Thalassinia.

When the ferocious shape-shifting Kraken awakes after thousands of years and threatens the Mer, Sapphire agrees to help them by going with her brother Conor and their friend Faro into the Deep to lull the monster back to sleep.

"Runa will not let her twin sister die. Alia traded her voice to the Sea Witch for a shot at happiness with a prince who doesn't love her. And his rejection will literally kill her--unless Runa intervenes. Under the sea, Evie craves her own freedom--but liberation from her role as Sea Witch will require an exchange she may not be willing to make. With their hearts' desires at odds, what will Runa and Evie be willing to sacrifice to save their worlds?...

What if Ariel had never defeated Ursula? It's been five years since the infamous sea witch defeated the little mermaid ... and took King Triton's life in the process. Ariel is now the voiceless queen of Atlantica, while Ursula runs Prince Eric's kingdom on land. But when Ariel discovers that her father might still be alive, she finds herself returning to a world--and a prince--she never imagined she would see again.--

Entries from the long-lost journal of Ven, a Nain youth, relate his adventures as he faces pirates and is rescued by a mermaid and a kindly sea captain who sends Ven to an inn, where he encounters fairies, ghosts, and other strange boarders.

When her mermaid mother is missing, Jade, who is afraid of the ocean, must come up with a plan to get her back on dry land.