Jean (Kiersey Clemons) washes ashore on a desolate island, having survived a harrowing ordeal. Alone and alone, she searches for shelter. She finds only the scattered remnants of a long-abandoned campsite, and, exhausted from her horrific journey, collapses, hoping for a peaceful rest. But night is the most dangerous time here. That's when the creature comes. When it slips out of the water, it must feed.