You are in the oceans of Africa, 70 million years ago.

The murky, shallow waters of the West African coast during the Late Cretaceous were deceptively calm, until you saw the shadow—long, dark, and moving faster than any reptile that size should. It was a Goronyosaurus, a terrifying, early mosasaur, and it had locked onto your research submersible.

Suddenly, it breached the water like a monstrous, primitive crocodile. Its jaws, packed with conical, bone-crushing teeth, slammed into the reinforced viewing port with a deafening thud, spiderwebbing the armored glass. You looked straight into its cold, reptilian eye, seeing the raw hunger and ferocity of a dominant predator…