Mount Orange, Florida, is famous for two things: freshwater springs, ideal for free divers, and the gruesome cold case murder of best friends, Bailey and Celeste, twenty years ago. Tru has always lived in the shadow of Bailey’s and Celeste's murders; they cast a permanent darkness over sunny Mount Orange.

But now those unsolved murders invade her every thought. It’s only when she’s deep underwater that she feels free. Then a stranger called Rio rolls into town.

And as the summer heat ignites, so does the spark between Tru and Rio…along with their other-worldy connection to Bailey and Celeste. But then someone begins stalking them. And if they keep digging into the past, Tru and Rio know that this time it could be their blood that makes the springs run red.