Legacy finds the team of young explorers out to reveal the secrets of an area removed from modern day maps and hidden behind electric fences. However, once they reach the center of the lake, they discover an island that harbors an abandoned facility with a horrific legacy: the island is home to a deadly predator eager to feast on those dumb enough to ignore the warnings. But before they can turn back, our hapless heroes get dragged into a battle for their lives — and will need to work together if they hope to survive.