Nate and Brooke Martin arrive at their summer cottage along the rapidly gentrifying Great Lakes shoreline. The beach is warm, the water is cool, and the sea breeze is blissful - perfect conditions for rekindling their strained relationship.
However, on a morning stroll along the beach, Nate finds an unusual gold coin half-buried in the sand. Where did it come from? Are there more?
Teaming up with reclusive ex-Coast Guard Officer and Great Lakes master of the deep, Abner Hutch, Nate dives for clues to the treasure's origins. But when word leaks that there may be a fortune hidden under the waves, they find themselves hunted by mega-rich residents up the coast who are willing to do anything to advance their extravagant lifestyles.
Will the Martins change their family's fortunes, or will the summer vacation end in a tragedy?