When the body of a man is found completely destroyed in the swamps in Louisiana, the medical investigator Sam Rivers is assigned to investigate the murder. He travels with the biologist Mary Callahan to the location where the victim lived in a floating house and he meets his family and friends. They find that Chinese snake-heads genetically engineered that belong to a wealthy hunter are attacking and killing the locals. While the group fights to survive, the hunter Jeff arrives with his team to hunt the predators.

After the death of his wife, world-class neurosurgeon Dr. Andrew Brown leaves Manhattan and moves his family to the small town of Everwood, Colorado. There he becomes a small-town doctor and learns parenting on the fly as he raises his talented but resentful 15-year-old son Ephram and his 9-year-old daughter Delia.