Fourteen-year-old Erika Magnus has always looked after her older sister, Sif, so when Sif longs to return home to the island of Rongo, Erika successfully plots to get her there.
Fourteen-year-old Riko manages to get her delicate older sister Sif and herself to their remote Pacific island home, where an American scientist who falls in love with Sif and discovers her connection with an underwater race creates complications in Riko's life.
