Invited to the world's only undersea research station, Ezzy, Luke, and their father head to the Florida Keys and dive into an unexpected adventure. While visiting their ex-military friends in the Aquarius Sea Station, Ezzy and Luke encounter a strange algae bloom at the surface, giant goliath groupers, and a mysterious fish that threatens the coral reefs and their own safety. It's another wild ride filled with humor and action as Ezzy Skylar explores the depths of her courage while overcoming her insecurities. With new friends, she and Luke discover the wonders of the undersea world and what it is like to live underwater. But once again they unwittingly stumble into a plot that could have disastrous consequences for the local wildlife and must jump into action to save the day.