Two Arkansas Fracking Industries (AFI) employees, Fred Robert Hummel and Sam Steve Goldenberg, are busy detonating explosives near the Arkansas State Prison for Women when they inadvertently release a shark covered in spikes into the surrounding swamp. As five inmates, Anita Cindy Lucas, Michelle Christine Nguyen, Sarah Skye McDonald, Shannon Amy Holt, and Samantha Tabitha Marie load up in a transport vehicle, the shark kills Fred and Sam. Detectives Kendra Patterson and Adam Levine comb the swamps for someone and find an overturned canoe, next to some human remains. Under the canoe is a man muttering “shark” repeatedly.
The corrections officers and the five prisoners arrive at an area where the prisoners are required to remove tree stumps. Samantha bribes Mike Serafin Falcon to let her go wash off her arm in the nearby creek, and she is eaten by the shark. Mike searches for her, finds only bloody clothes, and radios into the warden that she has escaped. Heading back to the prison, Anita's girlfriend Honey Dominique Swain hijacks the van and forces the two officers into the back with the others, letting Anita up front. Kendra Patterson and Adam Levine overhear on their scanner about the hijacking. Honey and Anita stop to change vehicles and make the women change. Mike escapes into the swamp but is eaten by the shark.
The prisoners arrive at a house where Honey has killed the occupant for them to hide out temporarily. While there, the girls argue amongst themselves and Sarah goes outside to the nearby creek when the shark appears. She runs off but the shark is able to burrow through the mud and bites her leg off. She bleeds out crawling back to the house and Michelle finds her body outside. They discover her severed leg nearby with a shark's tooth embedded in it, when suddenly two geologists, Professor Orville Chris De Christopher and his assistant John Oscar DeRosa, emerge from the trees saying their car was destroyed by a land shark. The geologists theorize that nearby explosions and fracking opened a “superhighway” between Earth's surface and an underground ocean, releasing a predator capable of hunting on land and in water. They try to make it to the van but the shark tunnels through the dirt forcing them back inside the house. Michelle uncovers a secret stash of assault weapons in the house and everyone takes a gun.
Outside, they discover there are several sharks now but spot a cave entrance off the back of the property. They use some of their ammunition's gunpowder to create a makeshift bomb with clothes they soak in some blood Carl Carl volunteers. This creates a distraction for them to run to the cave. When Orville sprains his ankle, John sacrifices himself so Carl and Honey can help the professor. Detectives Kendra and Adam arrive at the cabin but are attacked by the sharks and are forced to drive off. Inside the cafe, the others hear the sharks communicating the same way as whales. They discover a shaft of daylight and resolve to use a blow up raft they have to cross it when Orville gets eaten by a shark. In pairs, they make it across the water. Honey and Anita are the last to cross and Anita decides to shoot at Carl, Shannon, and Michelle as they are nearing the shore which causes her to lose her balance and fall into the water. Sharks attack, eating her and Honey while Shannon is struck by one of Anita's bullets and killed. Carl allows Michelle to leave. The detectives, who found maps of the cave somehow online, drive up to the exit where Carl is standing and they ask about the prisoners and Carl reports them all as dead. Kendra, at this point, is obsessing over “land sharks” and asks if Carl knows what they are up against and he nods. The final scene shows Honey crawling out from the water, having survived the shark attack before looking at the camera to deliver her catchphrase “crap on a cracker.”
> "crap on a cracker"
