On a frigid morning in Alaska, early in 1873, Junior Mackay's boss gives him the job a lifetime: take seven hundred tons of ice by steamship to Panama City, where people want their drinks cold and meat fresh. With his best friend Gideon Bell at his side, Junior sails farther than he's ever been and lands in one of the wildest places left on earth. It doesn't take long for their plans to go awry, and Junior and Gideon have to fight their way through a deadly jungle to Panama's other coast, before their precious cargo melts into water.