In northern Sumatra, marine biologist Skyler Shane teams up with Jack Bowman to search for prehistoric samples at a lake. Their expedition takes a dangerous turn when they encounter smugglers operating in the area. Tamal, an orphan sold into slavery by the smugglers, pleads with Skyler for help, evoking memories of Skyler’s lost daughter, Rebecca. Unbeknownst to them, a sinister secret lurks beneath the lake’s surface. Since Tamal’s arrival, mysterious disappearances have escalated, with more people falling prey to a terrifying creature lurking in the depths.