Adventure-seeking couple, Eric and Jennifer, convince their friends, Yolanda and Viktor, to explore an uncharted cave system in far North Australia, with the help of the unpredictable as their guide. The five spelunkers abseil into the deep mouth of the cave as a storm approaches, none are worried by the forecast, knowing they will be safe underground. But when the caves are flooded, they become disoriented and tensions rise as they struggle to find a way out. But dank air and rising water are the least of their worries, as they discover the storm as also brought in a hungry and territorial predator.
