The mystery of one of the most efficient eating and breeding machines in nature. This starfish eats only one thing - coral. It has already reached uncontrollable numbers over a large part of the Great Barrier Reef. Also under impact from global warming and coral bleaching, this diverse and delicate reef ecosystem is under extreme pressure. SWAT teams of divers try to keep ahead of the plague through poisoning, but the numbers are too great. It's now a race against time. Have the scientists finally found the reason for this freakish outbreak? What can be done? Without a solution, the largest reef structure on earth could soon be simply reduced to rubble.