You are in the deep oceans of North America, 75 million years ago.

The water at 500 meters was absolute black, colder than ice, and heavy with pressure. Your submersible’s lights were mere dust motes in the abyss. You were searching for signs of the Western Interior Seaway’s lost life when a massive shadow crossed the sonar—something nearly 30 feet long.

Suddenly, the lights caught it.

It wasn't a shark. It was a Tusoteuthis. The sheer size of this tentacled giant was hypnotic. Its mantle was enormous, pulsating slowly as it hung in the water, a remnant of a Cretaceous nightmare. Its eyes, likely the largest in the animal kingdom, caught the spotlight, turning with a calculated, cold intelligence. For a moment, you were locked in a staring contest…