You are in the seas of Europe, 155 million years ago.

The water over the Oxford Clay sea was a deceiving, tranquil turquoise. You, submerged in a research sub-capsule, monitor the depth as you descended 50 meters to the bottom of the ocean. The sonar was quiet, too quiet.

Just then, a school of fish scatter abruptly. The light changed. A massive shadow, larger than the capsule, rose from the dark blue depths below. It was a Liopleurodon. And it was ambushing. It flies through the water, its four massive flippers driving a 8-meter, streamlined body straight up with surprising, silent speed. You saw the 5-foot-long skull, teeth white and sharp as jagged rocks, eyes fixed upward, searching for the silhouette of prey.

It hit the water right next to the pod, not for a kill, but with a terrifying, investigative nudge, its snout scratching the titanium hull. You could feel the vibration. The creature was not a sleek dolphin-like hunter, but a brutal, reptilian torpedo, smelling the air-breathing life inside the craft using its keen sense of smell.