You are in the tundra grasslands of Siberia, 150,000 years ago.

The wind screamed across the Siberian steppe, carrying ice crystals that stung your exposed skin. You crouched behind the wind-bent larch, not just from the -30°C cold, but from what was feeding by the frozen riverbank.

It was colossal, easily twice the size of the woolly rhinos you sometimes saw—a shaggy, mountain-brown beast with a high, fatty hump on its shoulders. Its head was bowed, digging through the snow for frozen sedge grasses with a massive, pitch-black horn. The horn was terrifying—straight, smooth, and easily five feet long, rising from its forehead like a jagged peak.

Suddenly, it stopped grazing. The sheer size of its head swung toward your direction. Even from fifty paces, you saw its small, dark eyes focus on the treeline. A guttural snort, like thunder rolling over the tundra, erupted from its massive snout. It didn't look like a beast of the forest; it looked like a force of nature. You stay frozen, holding your breath. It stared for a heart-stopping moment, its massive frame tense, deciding whether to charge…