15 year old Quinn Perkins is ecstatic to be spending the summer working as an intern with her best friend Daniela and marine biologist father Charlie. The besties haven’t seen each other since Charlie inherited a research centre in Dolphin Cove, Australia. When Quinn arrives, she is surprised to learn that there are other interns joining them - Daniela’s new best friend Jennifer, and the adventurer wannabe Teddy.
Quinn is thrilled to be researching the reef’s unnatural shift in biodiversity, but things feel different between Quinn and Daniela, and it’s not long before Quinn agrees to join Teddy on a treasure hunt as a distraction. Mysterious things occur, and the teens assume that they are being haunted by local legend Everly Fallow. Curious, they find Everly’s daughter who gives them his journal containing a treasure map. The map reveals that to find the treasure, the reef must be destroyed, so they abandon their hunt and hide the journal. But the secret of the map is revealed, and the journal stolen, leading the four teens to uncover the truth about the mysterious Everly Fallow and what or who, is responsible for the problems on the reef.