It's around 300,000 years ago, during the Middle Paleolithic era, and we're in Kenya.
More specifically, southern Kenya, a region known as the Ology Basin.
Out here, the land is dry and barren.
A few trees dot the landscape, their thin trunks bent by the prevailing wind.
They're surrounded by low, scrubby bushes.
The grass and plants have been bleached a yellowy brown by the relentless sun and are surrounded by sharp, jagged rocks.
For now, there's little sign of any life, but that's about to change.
The patter of footsteps alerts you to the fact that your fellow tribesmen have returned.
As they jog towards you, their bare torsos glisten with sweat, their eyes screwed up against the blinding sunlight.
In their arms, they carry the treasure you've been waiting for.
The precious black stone obsidian.
They've obtained it from a nearby tribe who live near the source of this stone.
You hurry over to greet the men and relieve them of their goods.
It's your job to fashion this valuable stone into a collection of tools that can be used for cutting and slicing.
Once you're seated on a rock, the leaves of a nearby tree providing much needed shade, it's time to get to work.
The minutes stretch into hours as you deftly sharpen the ends of the obsidian into finite points.
Then you smooth their edges into sharp blades before wrapping vine and bark around the bases, forming a kind of handle.
Once the first tool has been created, you hold it up with pride, admiring the rays of sun that dance on its shiny black coat.
You hold it out to a fellow tribesman, who snatches it from your grasp and plunges it into an antelope carcass.
While you've been making tools, another group has returned from a hunt, carrying a number of mammals, both large and small.