What would you risk for the memory of your first love?

When Jenna Ross learns her high school love Del Soto died on Lemon Reef, she refuses to accept the official Miami medical examiner's report of death from natural causes.

Lemon Reef is a realm of glimmering beauty, where marine life triumphs over industrial waste. Del and Jenna dove on it every day during the summer before their tenth grade year, their love for the reef deepening as their passion for each other grew. It is a site of tenacity and wonder that mirrored their own, until they were outed and forced to separate. Even fifteen years later, Jenna knows that Del's heart could not have given out there.

Grief stricken over Del's death and fearing that Del's young daughter may be in danger, Jenna risks all she has worked so hard for to return to Miami where she must dive into an excruciating past so that the truth of the present may surface.