Dr. Thomas Clayton was born to an unwed teenage daughter of an Ozark share-cropper. He was adopted at birth without ever knowing the identity of his biological mother or of his backwoods roots. He now unwittingly arrives in the Ozark community of Eminence as part of an environmental research team studying the pollution effects of the logging industry. Clayton has nothing but contempt for the hillbillies of the area, while they in turn suspect that he is part of a Federal conspiracy to take over their land. Shot down by the military, an alien spaceship crashes into the Ozark Mountains. The alien crew is killed, but the destruction of the spacecraft allows an aggressive alligator-sized amphibian to escape into the continental aquifer which extends from Canada to Mexico. The amphibians quickly multiply and begin devouring the livestock and ultimately the citizens of Eminence. A military unit from Ft. Leonard Wood attempts to eradicate the aliens only to be destroyed themselves by the aggressive creatures. With the destruction of the military and the impending destruction of the citizenry, Clayton and the town folk join together to obliterate the creatures using only the resources available to a backwoods farming community. Failure would doom the entire nation as the amphibians could travel through the aquifer to wreak havoc throughout the country. With the annihilation of humanity in the balance, Clayton discovers the key to destroying the aliens. But using it would require him to intentionally spread the pollution he has sworn to prevent. In an explosive pyrotechnic battle with the creatures, Clayton wrestles with the morality of blatantly destroying a new species or somehow capturing it for preservation before it destroys mankind. Does he prevent the spread of pollution or proliferate its spread to save the world? In the process, Clayton makes a stunning discovery that brings him full-circle to his Ozark roots and the family he never knew.