Scientists discover a huge rift emitting energy at the bottom of the ocean floor in the Yucatan Peninsula. They send two research teams to investigate and they mysteriously disappear. A request made by their chief scientist Jenna Carter to the United States Navy prompts them to send their latest and most sophisticated ballistic missile submarine, the Barracuda, commanded by Captain Samuel Pike and aided by Jenna Carter and an new research team.
Deploying the civilian research submersible, it too is drawn into the energy rift. Captain Pike makes a split second decision and takes the Barracuda into the rift.
They find themselves back in time – 65 million years when dinosaurs ruled the earth…or so we thought. They discover in reality that the Earth is being terraformed by a hostile alien race who soon finds out the rift exists and begins plans of an invasion.
The Barracuda and her crew under all odds must find a way to stop the invasion, close the rift and return home.