But now a worrisome and potentially dangerous development has shown up on Charlie’s radar. Young Augustus Sweetwater, affectionately known as Augie, hasn’t reported in after completing a south-of-the-border sales trip for Sweetwater Marine. Raul, Augie’s father and Charlie’s nephew, is worried sick. Drug cartel violence in Mexico has reached epidemic proportions and Augie’s path took him through the heart of the narcotraficantes’ territory.

Charlie figures Augie just went off the grid to do some well-deserved fishing, surfing and beer-drinking at the end of his trip. He’d done the same in his time. But as Augie’s unexplained absence grows, Charlie and Raul become increasingly alarmed and set off for Mexico to bring their boy home.

What they unearth is far more than the sum of their fears. The familiar and friendly Gulf of Mexico has turned into a hidden sea plagued by smugglers, human traffickers, crooked politicians and even pirates. And Augie is lost somewhere in the middle of it all.

Charlie and Raul must summon an unlikely cast of characters to aid them, including a hilariously dissolute ex-pat musician, a priest whose faith struggles against the rising tide of refugee migration, a Mexican tycoon who may have secrets of his own and a beautiful maritime “repo man”. At the end of their quest, as the deepest secret of all is revealed, Charlie Sweetwater learns that neither Raul and Augie, nor the Gulf of Mexico, nor even himself, will ever be the same again.