Acid Horizon closely follows a deep sea explorer trying to save the planet. Dr. Erik Cordes is searching for a "Supercoral" that will survive Ocean Acidification and help prevent future extinctions. Is he too late? Acid Horizon follows marine ecologist Dr. Erik Cordes on a harrowing deep-sea expedition to track down the "supercoral", a strain of the deep-water coral Lophelia pertusa that seems to possess the unique genetic capability to thrive in a low-pH ocean.