An unknown pathogen leaves divers bleeding out from horrific wounds.A film of hot water no thicker than a child's wrist separates it from the open ocean.Its escape threatens to turn a day at the beach into a nightmare Hidden below the Mediterranean lies a warren of undersea trenches, punctuated by an explosive cluster of deep-water hydrothermal vents. But when a team of aquanauts return half-dead and covered in festering slashes, epidemiologist Leigh...