Despite a series of storms recently flooding the area, Sara, the planner amongst the partiers, is adamant on continuing with their exploration of the La Boca Del Diablo (The Devil’s Mouth) cenotes – a hauntingly intricate maze of deep underwater caverns. But as they traverse the awe-inspiring flooded caves and tunnels, looming in the depths below is a silent, swift, and bloodthirsty trapped outsider – a true apex predator. The group’s only hope for survival is to set aside their petty differences and work together to find their way out. But even then, do they stand a chance?