You are in the deep oceans of Europe, 183 million years ago.

The water of the early Jurassic was not empty. It was a cold, dim abyss, and you were holding your breath, suspended in a sea that felt entirely too quiet. You were monitoring the edge of a steep drop-off, where the sunlit surface water vanished into a deep, pitch-black chasm. Nearby, a small shoal of belemnites—squid-like creatures with hard, internal shells—drifted cautiously, their soft bioluminescence the only light.

Then, the lights went out. Not all at once, but one by one. The belemnites vanished instantly, spooked by an approaching presence.

From the blackness below, something emerged. It was 30 feet of pure, streamlined muscle, a shape so refined and sleek it seemed designed to break the laws of physics. A Temnodontosaurus.

It was massive, yet silent. Its front fins, wing-like and dark, had serrated trailing edges, designed to suppress noise just like an owl’s feathers. There was no thrashing, no displaced water, only a gliding, dark shadow that stole the light from the abyss.

Its eyes were the size of soccer balls, luminous in the dimness. They were locked on the terrified belemnites, but for a split second, they flickered toward you, as you wondered in fear whether or not it regards you as food…