Forty-year-old Leon Ross leaves the calm lakes of Maine for his first journey into the open Atlantic, expecting serenity among the islands of Casco Bay. Instead, a relentless current drags him beyond the safety of shore and into vast, indifferent waters. As night falls, Leon drifts through shipping lanes and into depths haunted by unseen predators. Alone, exhausted, and slowly losing hope, he must confront the terrifying truth that the ocean does not care whether he lives or dies.