Arlo takes his younger brother, Jude, camping before Jude goes off to college in the fall. But the lake where they pitch their tent has a creature lurking within it, waiting.

Jude is pulled beneath the water and violated by the creature, and Arlo dives in and rescues his brother, but not before the damage is already done.

Now, Jude needs Arlo to bring to an end what the creature began.