You are in the forested plains of North America, 2 million years ago.

The humid air of the early Pliocene savanna was thick with the scent of pine and marshwater. You were crouching near the edge by a freshwater lake, sketching a herd of horses that had recently wandered here to take a drink.

The savanna was quiet—too quiet. Just then, the wind shifted, and the small rodents that usually scampered through the sawgrass had vanished. Moments later, the horses become nervous, as they glance around their surroundings warily, before they panicked, bolting off back to the wilderness. It was then you begin to feel a vibration—a rhythmic and heavy thumping—travelling through the ground. You looked up, expecting a bison or perhaps a ground sloth.

It was not a mammal.

Standing on the opposite bank, fully eight feet tall, was a nightmare in feathers. A Titanis. Its body was covered in a mix of coarse, dull-brown feathers, but its legs were long, scaly, and powerful, built for running down prey. The most horrifying feature was its head—easily the size of a horse's head, armed with a massive, yellow-hooked beak, designed like a pickaxe.

The Titanis has spotted you. It did not roar like a mammalian predator; instead, it made a clicking sound in its throat, a dry, rattling noise that felt unnatural.

It took a step forward, its yellow gaze on you never wavering. It did not run. It paced, a slow, predatory walk. You realized too late that this bird was not a specialized scavenger; it was an ambush predator, having migrated from the south to rule this new landscape…