When she incurs Neptune's wrath by finding a diamond ring buried under rocks in the ocean, Emily is put under a curse that will force her to choose to be either a mermaid or a human and split up her parents forever.
Philippa Fisher, who wants to be able to summon a fairy, is surprised when Daisy, the new girl at school, says she is her fairy godmother--or godsister--who is grudgingly committed to grant three wishes, and Philippa struggles to wish for something that will improve her life instead of making it more difficult.
When Neptune tells Emily and her merman father and human mother to return to Brightport to try to make merpeople and humans work more closely together, Emily faces problems with old enemies, her new, half-merfolk friend Aaron, and a mystery related to a group of legendary lost sirens.
Twelve-year-old Jenni's much-anticipated vacation with her family and best friend Autumn goes awry when an old elevator transports her to a future in which everything has changed, and she must not only return to her time but find a way to prevent what she has seen from coming true.
When Emily makes a wish on a magic stone, she gets a glimpse of what the future holds--and it's a disaster! She tries to make things right, but each trip through time takes Emily to a future where things turn out badly for either the humans of Brightport or the merpeople of Shiprock. Plastic pollutes the ocean, garbage overflows the landfills, and the two towns are no longer getting along. Emily realizes she can't save her hometown and the ocean alone,...
Philippa Fisher learns that friendships can be tricky when she finds herself trying to deal with the odd behaviors of her old friend and fairy godsister Daisy, and her new friend Robyn, a sad and secretive girl.