In a small coastal town, the community eagerly anticipates the opening of a new cannery, which promises economic revitalization. However, their hopes are soon overshadowed by strange occurrences. Fishermen report unusually aggressive fish in the waters, and soon town residents begin to vanish mysteriously. The town's unusually high number of disappearances raises alarm bells, leading local scientist Dr. Susan Drake to investigate. Alongside fisherman Jim Hill, she discovers that genetic experiments on salmon, intended to accelerate their growth for the cannery, have gone horribly wrong. These experiments have inadvertently created humanoid sea creatures that are now emerging from the deep, driven by a terrifying instinct.

As these monstrous entities wreak havoc, the town finds itself in a fight for survival. Tensions rise as different factions argue over the causes and solutions to the escalating crisis. Meanwhile, the creatures become increasingly bold in their attacks, targeting human beings both in the water and on land. The community is forced to confront the terrifying consequences of their industrial ambitions, which have now unleashed a deadly force upon them. With limited resources and growing panic, the townspeople must devise a plan to combat the humanoid menace before it completely overtakes them.